Exam 6: Work and Energy

A very light ideal spring stretches by 21.0 cm when it is used to hang a 135-N object. What is the weight of a piece of electronic equipment that would stretch the spring by 44.9 cm if you hung the Equipment using the spring?

(Multiple Choice)

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Question 21

An ideal spring with a force constant (spring constant) of 15 N/m is initially compressed by 3.0 cm from its uncompressed position. How much work is required to compress the spring an additional 4)0 cm?

(Multiple Choice)

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Question 22

What is the minimum energy needed to change the speed of a 1600-kg sport utility vehicle from 15.0 m/s to 40.0 m/s?

(Multiple Choice)

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Question 23

A person carries a 2.00-N pebble through the path shown in the figure, starting at point A and ending at point B . The total time from A to B is 6.75 min. How much work did gravity do on the rock between A and B ?

(Multiple Choice)

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Question 24

A 1500-kg car moving at 25 m/s hits an initially uncompressed horizontal ideal spring with spring constant (force constant) of $2.0 \times 10 ^ { 6 } \mathrm {~N} / \mathrm { m }$ What is the maximum distance the spring compresses?

(Multiple Choice)

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Question 25

A stone initially moving at 8.0 m/s on a level surface comes to rest due to friction after it travels 11 m. What is the coefficient of kinetic friction between the stone and the surface?

(Multiple Choice)

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Question 26

If a spring-operated gun can shoot a pellet to a maximum height of 100 m on Earth, how high could the pellet rise if fired on the Moon, where g = 1.6 m/s²?

(Multiple Choice)

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Question 27

A prankster drops a water balloon from the top of a building. If the balloon is traveling at 29.1 m/s when it strikes a window ledge that is 1.5 m above the ground, how tall is the building? Neglect air Resistance.

(Multiple Choice)

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Question 28

Jill does twice as much work as Jack does and in half the time. Jill's power output is

(Multiple Choice)

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Question 29

A heavy dart and a light dart are launched horizontally on a frictionless table by identical ideal springs. Both springs were initially compressed by the same amount. Which of the following Statements about these darts are correct? (There could be more than one correct choice.)

(Multiple Choice)

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Question 30

A force of 30 N stretches a very light ideal spring 0.73 m from equilibrium. What is the force constant (spring constant) of the spring?

(Multiple Choice)

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Question 31

What is the minimum energy needed to lift a 1.0-kg rocket to a height of 200 km and to give it a speed of 8.0 km/s at that height? (Neglect air resistance and the small decrease in g over that Distance.)

(Multiple Choice)

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Question 32

Two cyclists who weigh the same and have identical bicycles ride up the same mountain, both starting at the same time. Joe rides straight up the mountain, and Bob rides up the longer road that Has a lower grade. Joe gets to the top before Bob. Ignoring friction and wind resistance, which one Of the following statements is true?

(Multiple Choice)

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Question 33

A block slides down a frictionless inclined ramp and experiences no significant air resistance. If the ramp angle is 17.0° above the horizontal and the length of the surface of the ramp is 20.0 m, find The speed of the block as it reaches the bottom of the ramp, assuming it started sliding from rest at The top.

(Multiple Choice)

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Question 34

A 1-kg ball is released from a height of 6 m, and a 2-kg ball is released from a height of 3 m. Air resistance is negligible as they fall. Which of the following statements about these balls are correct? (There could be more than one correct choice.)

(Multiple Choice)

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Question 35

A sand mover at a quarry lifts 2,000 kg of sand per minute a vertical distance of 12 m. The sand is initially at rest and is discharged at the top of the sand mover with speed 5.0 m/s into a loading Chute. What minimum power must be supplied to this machine?

(Multiple Choice)

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Question 36

A typical incandescent light bulb consumes 75 W of power and has a mass of 30 g. You want to save electrical energy by dropping the bulb from a height great enough so that the kinetic energy of the bulb when it reaches the floor will be the same as the energy it took to keep the bulb on for 1.0 hour. From what height should you drop the bulb, assuming no air resistance and constant g?

(Short Answer)

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Question 37

An ornament of mass 40.0 g is attached to a vertical ideal spring with a force constant (spring constant) of 20.0 N/m. The ornament is then lowered very slowly until the spring stops stretching. How much does the spring stretch?

(Multiple Choice)

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Question 38

It takes 87 J of work to stretch an ideal spring from 1.4 m to 2.9 m from equilibrium. What is the value of the spring constant (force constant) of this spring?

(Multiple Choice)

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Question 39

A force produces power P by doing work W in a time T . What power will be produced by a force that does six times as much work in half as much time?

(Multiple Choice)

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Question 40

Showing 21 - 40 of 153

Exam 6: Work and Energy

A very light ideal spring stretches by 21.0 cm when it is used to hang a 135-N object. What is the weight of a piece of electronic equipment that would stretch the spring by 44.9 cm if you hung the Equipment using the spring?

An ideal spring with a force constant (spring constant) of 15 N/m is initially compressed by 3.0 cm from its uncompressed position. How much work is required to compress the spring an additional 4)0 cm?

What is the minimum energy needed to change the speed of a 1600-kg sport utility vehicle from 15.0 m/s to 40.0 m/s?

A person carries a 2.00-N pebble through the path shown in the figure, starting at point A and ending at point B . The total time from A to B is 6.75 min. How much work did gravity do on the rock between A and B ?

A 1500-kg car moving at 25 m/s hits an initially uncompressed horizontal ideal spring with spring constant (force constant) of 2.0×106 N/m2.0 \times 10 ^ { 6 } \mathrm {~N} / \mathrm { m }2.0×106 N/m What is the maximum distance the spring compresses?

A stone initially moving at 8.0 m/s on a level surface comes to rest due to friction after it travels 11 m. What is the coefficient of kinetic friction between the stone and the surface?

If a spring-operated gun can shoot a pellet to a maximum height of 100 m on Earth, how high could the pellet rise if fired on the Moon, where g = 1.6 m/s²?

A prankster drops a water balloon from the top of a building. If the balloon is traveling at 29.1 m/s when it strikes a window ledge that is 1.5 m above the ground, how tall is the building? Neglect air Resistance.

Jill does twice as much work as Jack does and in half the time. Jill's power output is

A heavy dart and a light dart are launched horizontally on a frictionless table by identical ideal springs. Both springs were initially compressed by the same amount. Which of the following Statements about these darts are correct? (There could be more than one correct choice.)

A force of 30 N stretches a very light ideal spring 0.73 m from equilibrium. What is the force constant (spring constant) of the spring?

What is the minimum energy needed to lift a 1.0-kg rocket to a height of 200 km and to give it a speed of 8.0 km/s at that height? (Neglect air resistance and the small decrease in g over that Distance.)

A 1-kg ball is released from a height of 6 m, and a 2-kg ball is released from a height of 3 m. Air resistance is negligible as they fall. Which of the following statements about these balls are correct? (There could be more than one correct choice.)

A sand mover at a quarry lifts 2,000 kg of sand per minute a vertical distance of 12 m. The sand is initially at rest and is discharged at the top of the sand mover with speed 5.0 m/s into a loading Chute. What minimum power must be supplied to this machine?

An ornament of mass 40.0 g is attached to a vertical ideal spring with a force constant (spring constant) of 20.0 N/m. The ornament is then lowered very slowly until the spring stops stretching. How much does the spring stretch?

It takes 87 J of work to stretch an ideal spring from 1.4 m to 2.9 m from equilibrium. What is the value of the spring constant (force constant) of this spring?

A force produces power P by doing work W in a time T . What power will be produced by a force that does six times as much work in half as much time?

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A 1500-kg car moving at 25 m/s hits an initially uncompressed horizontal ideal spring with spring constant (force constant) of $2.0 \times 10 ^ { 6 } \mathrm {~N} / \mathrm { m }$ What is the maximum distance the spring compresses?