Physics Energy Review

Physics Energy Review

Multiple Choice

The chart represents the work output and the time to do the work for four machines.

For which machine is the power output least?

• I

• II

• III

• IV

Multiple Choice

A 290-N force is used to compress a spring. The spring constant of the spring is 5,880 N/m. How far is the spring compressed?

• 0.0050 m

• 0.049 m

• 0.31 m

• 20. m

Multiple Choice

A ball is released from the top of an inclined plane as shown below. Ignoring friction, where will het potential energy (PE) and kinetic energy (KE) of the ball be at a maximum?

• PE at J, KE at M

• PE at K, KE at L

• PE at L, KE at K

• PE at M, KE at J

Multiple Choice

A 588-N person carrying 294 N of equipment starts climbing a mountain that is 3,118 m high. What is the minimum energy required for the person to climb the mountain?

• 2.81 x10^5 J

• 9.17 x 10^5 J

• 1.83 x 10^6 J

• 2.75 x 10^6 J

Multiple Choice

A machine lifts a 35-kg object 20.0 m in 2.0 s. How much power is produced by the machine to lift the object?

• 350 W

• 890 W

• 3,400 W

• 6,900 W

Multiple Choice

A force of 50 N is required to hold an ideal spring stationary after the spring has been stretched 0.1 m from its equilibrium position. How much potential energy is stored in the stretched spring?

• 50 J

• 25 J

• 5.0 J

• 2.5 J

Multiple Choice

How much power does it take to lift a 12-N object 0.87 m in 1.3 s?

• 0.80 W

• 8.0 W

• 10. W

• 18 W

Multiple Choice

A 2.00-kg brick falls from the top of a building 6.00 m above the ground. What is the kinetic energy of the brick just before it reaches the ground?

• 118 J

• 58.8 J

• 12.0 J

• 3.00 J

Multiple Choice

A constant 3.0-N horizontal force is applied to a 0.10-kg object as it moves a distance of 0.20 m along a horizontal, frictionless surface. How much work does the force perform on the object?

• 6.0 × 10^–2 J

• 3.0 × 10^–2 J

• 6.0 × 10^–1 J

• 3.0 × 10^–1 J

Multiple Choice

A student walked up a flight of stairs. Later, the same student ran up the same flight of stairs in less time. What can be concluded about the relative amounts of work performed and power produced by the student in these instances?

• The work performed was the same in both instances. The power was greater when the student ran up the stairs.

• The work performed was greater when the student ran up the stairs. The power was the same in both instances.

• The work and power were the same in both instances because it was the same student on the same stairs.

• The work performed and the power produced were both less when the student was running up the stairs than when walking up the stairs.