The efficiency of a screw is low because of _____.
width
friction
length
height
Answer:
The efficiency of a screw is low because of friction.
Explanation:
A screw is a simple machine that is used to convert a torque to linear force and rotational motion to linear motion. The efficiency of a screw is given by :
[tex]\eta=\dfrac{Fl}{2\pi T}[/tex]
Where
l = pitch distance in mm
T = torque in N-m
The efficiency of screw is less because the output is less as compared to input or there is more input than output. This implies that there is more friction.
Hence, the correct option is (b) "friction".
A falling skydiver has a mass of 105 kg. What is the magnitude of the skydiver's acceleration when the upward force of air resistance has a magnitude that is equal to one-half of his weight?
The magnitude of the skydiver's acceleration when the upward force of air resistance is half of his weight is 4.9 m/s² downward. This is found using Newton's Second Law and the skydiver's weight calculated from his mass and the acceleration due to gravity.
Explanation:When the upward force of air resistance is equal to one-half of the skydiver's weight, the net force on the skydiver is only half of his weight acting downward. The skydiver's weight (W) can be calculated using the equation W = mg, where m is the mass and g is the acceleration due to gravity. For a mass (m) of 105 kg and assuming the acceleration due to gravity (g) is approximately 9.8 m/s2, the skydiver's weight would be 105 kg × 9.8 m/s2 = 1029 N. Half of this weight is 1029 N / 2 = 514.5 N.
According to Newton's Second Law (F = ma), the net force is equal to the mass multiplied by the acceleration. In this case, the net force is also the unbalanced force acting on the skydiver, which is half the skydiver's weight. Therefore, we have F = ma, which means 514.5 N = 105 kg × a. Solving for a, the acceleration, we get a = 514.5 N / 105 kg which is approximately 4.9 m/s2. Therefore, the magnitude of the skydiver's acceleration in this case is 4.9 m/s2 downward.
A VW Beetle goes from 0 to 60.0 mi/h with an acceleration of +2.35 m/s^2. (a) How much time does it take for the beetle to reach this speed? (b) A top-fuel dragster can go from 0 to 30 mi/h in 0.600 s. Find the acceleration (in m/s^2) of the dragster?
The VW Beetle takes 25.53 seconds to reach a speed of 60.0 mi/h with an acceleration of 2.35 m/s². The top-fuel dragster has an acceleration of 22.36 m/s² to go from 0 to 30 mi/h in 0.600 seconds.
Explanation:To calculate the time it takes for the VW Beetle to reach a speed of 60.0 mi/h, we need to use the equation v = u + at, where v is the final velocity, u is the initial velocity, a is the acceleration, and t is the time taken. Rearranging the equation to solve for t, we have t = (v - u) / a. Plugging in the values, we get t = (60.0 mi/h - 0) / 2.35 m/s² = 25.53 s.
To find the acceleration of the top-fuel dragster, we use the equation a = (v - u) / t, where a is the acceleration, v is the final velocity, u is the initial velocity, and t is the time taken. Rearranging the equation to solve for a, we have a = (v - u) / t. Plugging in the values, we get a = (30 mi/h - 0) / 0.600 s = 50 mi/h/s = 22.36 m/s².
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what two kinds of motion combine to to produce projectile motion
The theory of plate tectonics developed in part from an earlier hypothesis about how continents move. What is the name of this earlier hypothesis?
A.
continental drift
B.
earthquake development
C.
natural selection
D.
evolution
its A i know my science
Why is the combination of two protons and two neutrons stable, but two protons and one neutron is not?
Answer:
There are not enough neutrons to overcome the electrical repulsion of the protons.
Explanation:
Neutrons help stabilize a nucleus by attracting other nucleons (protons and neutrons). Although protons also attract other nucleons using the strong nuclear force, they repel other protons with the electrical force.
Hope this helps!
A rock is dropped from a bridge. what happens to the magnitude of the acceleration and the speed of the rock as it falls?
Which of the following is the correct unit for force?
A. Watts
B. Joules
C. Meters
D. Newton
Does gravity increase or decrease with greater distance?
If you wanted to increase the gravitational force between two objects what would you do
it would decrease the distance
If two objects are traveling at the same speed, why might one object have more inertia than another object? Give an example of two objects for which this is true?
Answer:
The object has larger mass. Examples would be like-cars of a different build driving at the same mph, or animals that typically run at the same speed but have different weights.
Explanation:
The more inertia that an object has, the more mass that it has.
if i jump on a trampoline. is it an inelastic or elastic collision?
what units is length in
Which of the rays drawn above would be correct as the light goes from the air into the water?
A, B, or C ??
The correct answer you are looking for is "A". Have a great day!
Answer:a
Explanation:test
A brass washer has an outside diameter of 4.50 cm with a hole of diameter 1.25 cm and is 1.50 mm thick. The density of brass is 8599 kg/m3. If you put this washer on a laboratory balance, what will it "weigh" in grams?
Final answer:
The weight of the brass washer is 82.3 grams.
Explanation:
The weight of the brass washer can be calculated using its density and volume. The volume of the washer can be found by subtracting the volume of the hole from the volume of the outer cylinder. The formula for the volume of a cylinder is πr^2h, where r is the radius and h is the height.
Given that the outside diameter is 4.50 cm, the radius is half of that, which is 2.25 cm (or 0.0225 m). The height of the washer is 1.50 mm, which is 0.0015 m. Using these values, we can calculate the volume of the washer:
Volume = π(0.0225)^2(0.0015) = 9.5747 x 10^-6 m^3
Now, we can calculate the weight of the washer using its volume and density:
Weight = Volume x Density = 9.5747 x 10^-6 m^3 x 8599 kg/m^3 = 82.3 g
Final answer:
The weight of the brass washer on a laboratory balance would be 59.5 grams.
Explanation:
To find the weight of the brass washer, we need to calculate its volume and then multiply it by the density of brass. The volume of the washer can be found by subtracting the volume of the hole from the volume of the outside part of the washer.
The volume of the outside part of the washer can be calculated using the formula for the volume of a cylinder: V = π[tex]r^2[/tex]h. In this case, the radius (r) is half the outside diameter, so r = 4.50 cm / 2 = 2.25 cm = 0.0225 m. The height (h) is the thickness of the washer, which is 1.50 mm = 0.0015 m. Plugging these values into the formula gives us V = π(0.0225 [tex]m^2[/tex](0.0015 m) = 7.21 x [tex]10^{-6}[/tex] [tex]m^3[/tex].
The volume of the hole can also be found using the formula for the volume of a cylinder, since it is cylindrical in shape. The radius (r) of the hole is half the hole diameter, so r = 1.25 cm / 2 = 0.0125 m. The height (h) of the hole is the same as the thickness of the washer, which is 0.0015 m. Plugging these values into the formula gives us V = π(0.0125 [tex]m^2[/tex](0.0015 m) = 2.94 x [tex]10^{-7}[/tex] [tex]m^3[/tex].
Now, we can find the volume of the washer by subtracting the volume of the hole from the volume of the outside part: V_washer = 7.21 x [tex]10^{-6} m^3[/tex] - 2.94 x [tex]10^{-7} m^3[/tex] = 6.92 x [tex]10^{-6} m^3[/tex].
Finally, we can calculate the weight of the washer using the formula W = V_washer * density. Plugging in the values gives us W = 6.92 x [tex]10^{-6} m^3[/tex] * 8599 kg/[tex]m^3[/tex] = 5.95 x [tex]10^{-2}[/tex] kg = 59.5 g.
The gravitational force between a satellite and Earth’s moon is 324 N. The mass of the moon is 7.3 × 1022 kg. If the distance from the moon to the satellite is 2.6 × 106 m, what is the mass of the satellite?
Answer:
449.824 kg
Explanation:
F = Gm₁m₂/r²
Above equation can be used to find the gravitational force between two objects.
Here F is the Gravitational force. m₁ , m₂ are the masses of the objects and r is the distance between the objects. Let's take m₁ as the mass of the moon. Then m₂ is the mass of the satellite.
We are given that F = 324 N , m₁ = 7.3 * 10²²kg and r = 2.6 * 10 ⁶m.
324 = 6.67×10⁻¹¹ × m₁ × 7.3×10²² / (2.6 × 10⁶)²
m₁ = 449.824 kg
Answer:
answer above is right just round its 450kg
Explanation:
a projectile is fired with an initial speed of 500m/s and angle of elevation 30 degrees. find the range, max height and speed at impact
To find the range, maximum height, and speed at impact of a projectile fired with an initial speed of 500m/s and angle of elevation 30 degrees, we can use the equations of projectile motion.
Explanation:To find the range, maximum height, and speed at impact of a projectile fired with an initial speed of 500m/s and angle of elevation 30 degrees, we can use the equations of projectile motion.
Range: The horizontal distance covered by the projectile is the range. In this case, we can use the formula:
R = (V02 * sin(2θ)) / g
where R is the range, V0 is the initial speed, θ is the angle of elevation, and g is the acceleration due to gravity.
Substituting the given values into the formula, we have:
R = (5002 * sin(2 * 30)) / 9.8
R = (250000 * sin(60)) / 9.8
R ≈ 1450.83 meters
Maximum Height: The maximum height reached by the projectile can be found using the formula:
H = (V02 * sin2(θ)) / (2 * g)
Substituting the given values into the formula:
H = (5002 * sin2(30)) / (2 * 9.8)
H ≈ 3060.45 meters
Speed at Impact: The speed at impact is the magnitude of the velocity of the projectile when it hits the ground. Since the projectile is fired at an angle and lands at a lower height than its initial position, the speed at impact will be lower than the initial speed. However, we need more information to calculate the exact speed at impact.
A car travels around a racetrack at aconstant speed. During what parts of the coursedoes the car experience acceleration?
Answer:
If the racetrack’s length is 36 inches and is set to a height of 8 inches, 16 inches and 24 inches and each roll of the toy car is 7.8 seconds, 7.3 seconds and 6.6 seconds respectively, then, it only shows that the higher the racetrack, the faster the toy car will roll down because velocity, which measures how fast something is moving, is affected by gravity. Motion, as shown in this kind of scenario, is a kind of concept that depicts movement or change in position under given circumstances or factors over a period of time.
Explanation:
Can someone please help me how to set this up?
A police car receives a radio call to catch a vehicle which is speeding down the highway at 80 mph. The police car, which is 12 miles away, drives after it at 108 mph. How long will it take for the police car to catch up? ...?
Answer:
The time is 0.428 hr.
Explanation:
Given that,
Final speed = 108 mph
Initial speed = 80 mph
Distance = 12 miles
We need to calculate the time
Using formula of time
[tex]v = \dfrac{d}{t}[/tex]
d = distance
t = time
Put the value into the formula
[tex]108-80=\dfrac{12}{t}[/tex]
[tex]t = \dfrac{12}{108-80}[/tex]
[tex]t =0.428\ hr[/tex]
Hence, The time is 0.428 hr.
Classify which is specific defense or nonspecific defense:
- skin
- macrophages
- bacteria
- mucous
- fever
- B cells
- T cells
- antibodies
Which best describes the difference between internal and thermal energy?
Internal energy is the total potential and kinetic energies in a substance, and thermal energy is the part of internal energy that can be transferred to another substance. The answer on edge would be C.
How much work is done when a 48-kg stack of books are lifted 2m with a net force of 25 N ?
A. 12.4 J
B. 100 J
C. 50 J
D. 96 J ...?
Answer:
C). W = 50 J
Explanation:
As we know that the work done is the product of force and displacement
so here it is given that the net force on the stack of books is 25 N
[tex]F = 25 N[/tex]
also the displacement of the stack of books is 2m as it is lifted upwards
so we have
[tex]d = 2 m[/tex]
now by the formula of work done we know
[tex]W = F.d[/tex]
now plug in all values in it
[tex]W = (25)(2)[/tex]
[tex]W = 50 J[/tex]
An archer pulls back the string of a bow to release an arrow at a target. Which kind of potential energy is transformed to cause the motion of the arrow?
Answer: elastic potential energy
Explanation:
The form of energy stored in the string of the bow is elastic potential energy. Elastic potential energy is the energy stored in an elastic object (such as the string of a bow) when the object is compressed/stretched by a certain amount x with respect to its natural length. The elastic potential energy stored in the object is given by
[tex]U=\frac{1}{2}kx^2[/tex]
where k is the spring constant of the elastic string, and x is the compression/stretching.
Which of the following best defines volume?
A. The amount of matter in a substance.
B. The shape of a sample of matter.
C. The amount of space that a sample of matter takes up.
D. The way that a substances atoms are arranged Which of the following best defines volume?
A. The amount of matter in a substance.
B. The shape of a sample of matter.
C. The amount of space that a sample of matter takes up.
D. The way that a substances atoms are arranged
Answer:
C. The amount of space that a sample of matter takes up.
Explanation:
Volume is defined as the 3 dimension shape which is enclosed by a closed surface. It is defined that the space which is occupied by the substance.
The volume is defined in the cubic units.
The volume of container generally is the classification of the amount of space which the substance hold rather than the space which is displaced by the container itself.
Volume is the amount of space that a sample of matter takes up.
Explanation:Volume is best defined as the amount of space that a sample of matter takes up. It is a measure of how much space an object occupies. Volume can be expressed in different units such as cubic meters, liters, or milliliters.
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based on the law of conservation of energy. how can we reasonably improve a machines ability to do work? A.move the machine to a different gravitational field B.increase the friction between its moving parts C. reduce the friction between its moving parts or D. redefine the machines system boundaries?
The correct answer is
C. reduce the friction between its moving parts
In fact, by reducing the friction between the moving parts of the machine, it is possible to reduce the energy wasted due to this friction; therefore, more input energy is converted into useful work, and this will improve the efficiency of the machine.
Answer: We can reasonably improve a machines ability to do work by reducing the friction between the moving parts of machine. The correct answer is C.
Explanation:
According to the law of conservation of energy, the energy can neither be created nor destroyed. The energy can be converted from one form to another.
The energy is wasted due to the friction. It reduces the efficiency of the machines to do the work. There will be energy loss due to the friction. By reducing the friction, More energy can be converted into the work.
Therefore, we can reasonably improve a machines ability to do work by reducing the friction between the moving parts of machine.
A hydraulic press for compacting powdered samples has a large cylinder which is 10.0 cm in diameter, and a small cylinder with a diameter of 2.0 cm. A lever is attached to the small cylinder as shown in The sample, which is placed on the large cylinder, has an area of 4.0 cm2.
What is the pressure on the sample if F = 270 N is applied to the lever?
The hydraulic pressure on sample is [tex]3.35*10^{7} N/m^{2}[/tex].
What is hydraulic pressure?Hydraulic pressure is the force imparted per unit area of a liquid on the surfaces which it has contact.
The magnitude of force acting on the small cylinder is equal to [tex]F_{N}[/tex].
In static equilibrium, all the torques should add up to zero:[tex]F_{N}l - 270(2l)= 0\\F_{N} = 270(2)\\F_{N} = 540 N[/tex]
The pressure applied to the fluid (through the small cylinder):
[tex]P= \frac{540}{\pi (\frac{2*10^{-2} }{2} )^2}[/tex]
[tex]P = 1.71*10^{6} Pa[/tex]
The force of fluid on the large cylinder:
[tex]F= P\pi R^{3} \\F= 1.71*10^{6} \pi (0.05^{2} )\\F= 1.34*10^{4} N[/tex]
The pressure on the sample:
[tex]P_{S} =\frac{F}{A} \\P_{S}= \frac{1.34*10^{4} }{4*10^{-4} } \\P_{S}= 3.35*10^{7} N/m^{2}[/tex]
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An object is dropped from a 400-ft tower.
a) when does it hit the ground?
b) how fast is it going at the time of impact?
So,a)It will hit ground at 4.52seconds.b)At 145 ft/s fast is it going at the time of impact
An object is dropped from a 400-ft tower:
a) When does it hit the ground? Using the formula: time = [tex]\sqrt[1]{2*height/g}[/tex], where g is the acceleration due to gravity (32 ft/s²), the time taken to hit the ground is approximately 4.52 seconds.
b) How fast is it going at the time of impact? The velocity of the object when it hits the ground can be calculated as velocity = g * time, which gives a velocity of about 145 ft/s.
Which of the following best describes the difference between speed and acceleration? A. Acceleration is the distance an object travels within a specific unit of time, whereas speed is the rate at which the acceleration or direction of an object is changing.
B. Speed is the distance an object travels within a specific unit of time, whereas acceleration is the rate at which the speed or direction of an object is changing.
C. Acceleration is the distance an object travels within a specific unit of time, whereas speed is a measure of the force necessary to change the acceleration of an object.
D. Speed is the distance an object travels within a specific unit of time, whereas acceleration is a measure of the force necessary to change the speed of an objectWhich of the following best describes the difference between speed and acceleration? A. Acceleration is the distance an object travels within a specific unit of time, whereas speed is the rate at which the acceleration or direction of an object is changing.
B. Speed is the distance an object travels within a specific unit of time, whereas acceleration is the rate at which the speed or direction of an object is changing.
C. Acceleration is the distance an object travels within a specific unit of time, whereas speed is a measure of the force necessary to change the acceleration of an object.
D. Speed is the distance an object travels within a specific unit of time, whereas acceleration is a measure of the force necessary to change the speed of an object.
Answer:
Speed is the distance an object travels within a specific unit of time, whereas acceleration is the rate at which the speed or direction of an object is changing.
(Apex) Pretest
The option that best describes the difference between speed and acceleration is : ( B ) Speed is the distance an object travels within a specific unit of time, whereas acceleration is the rate at which the speed or direction of an object is changing.
Difference between and Acceleration and SpeedAcceleration is the rate of change of velocity with time while speed is the rate of change distance with time.
Acceleration is a vector quantity because it has magnitude and direction while speed is a scalar quantity.
Hence we conclude that Speed is the distance an object travels within a specific unit of time, whereas acceleration is the rate at which the speed or direction of an object is changing.
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Shawn runs 4 times around a 400 meter oval track and stops at the same point he sstarted
you did 150 joules of work lifting a 120 -N backpack.
how high did you lift the backpack?
how much did the backpack weigh in pounds
The backpack was lifted 1.25 meters high, and it weighed approximately 26.977 pounds.
To determine how high you lifted the backpack, we can use the formula for work done against gravity, which is W = F × h, where W is work (in joules), F is force (in newtons), and h is height (in meters). Since you did 150 joules of work to lift a 120-N backpack, we can rearrange the formula to solve for height (h): h = W / F = 150 J / 120 N = 1.25 meters. You lifted the backpack 1.25 meters high.
To find out how much the backpack weighed in pounds, we use the conversion factor that 1 newton is approximately equal to 0.224809 pounds. Therefore, 120 N × 0.224809 lb/N = 26.977 pounds. The backpack weighed approximately 26.977 pounds.