AP Physics Reviews by Topic

To calculate the kinetic energy of an object you must use this equation: E_k = 0.5 x mass x speed². Which of the following objects has the most kinetic energy?

• A 10 kg mass with a speed of 5 m/s.

• A 5 kg mass with a speed of 10 m/s.

• A 2 kg mass with a speed of 20 m/s.

• A 0.1 kg mass with a speed of 100 m/s.

Tags

NGSS.MS-PS3-1

To calculate the gravitational potential energy of an object you must use the equation: Ep = mass x gravitational field strength x height. Which of the following objects has the most gravitational potential energy?

• A 3 kg mass, 5 m above the ground on Earth (g = 9.8 N/kg)

• A 4 kg mass, 4 m above the ground on Venus (g = 8.9 N/kg)

• A 10 kg mass, 5 m above the ground on Mars (g = 3.4 N/kg)

• A 9 kg mass, 11 m above the ground on the Moon (g = 1.6 N/kg)

Tags

NGSS.MS-PS3-2

Which of the following is NOT a store of energy?

• Kinetic

• Gravitational Potential

• Elastic potential

• Thermal

• Sound

Which of the following is NOT a transfer of energy?

• Heating

• Kinetically

• Mechanically

• Electrically

• Waves

Tags

NGSS.MS-PS3-5

NGSS.MS-PS3-4

NGSS.MS-PS3-3

To calculate the elastic potential energy you must use the equation: E_e = 0.5 x spring constant x extension². (Extension must be in metres, m) Calculate the elastic potential energy stored in a spring with a spring constant of 200 N/m that has been stretched from a length of 117 cm to a length of 127 cm.

• 0.1 J

• 1.0 J

• 10.0 J

• 100.0 J

A toaster takes 200 s to transfer 180,000 J of energy. What is the power of the toaster?

• 90 W

• 900 W

• 9,000 W

• 90,000 W

Tags

NGSS.MS-PS3-4

An electric motor transfers 24 J of energy usefully, but wastes 16 J of energy in doing so. What is the efficiency of the motor?

• 16 J ÷ 24 J = 0.67

• 24 J ÷ 16 J = 1.5

• 16 J ÷ 40 J = 0.4

• 24 J ÷ 40 J = 0.6

Tags

NGSS.MS-PS3-5

What would an efficiency of 0% tell you about the energy transfers of a device?

• The device is not working.

• The device is not working in the way that it was designed.

• There is not enough energy being transferred for the device to work.

• All the energy that is transferred is to an unwanted energy store.

Tags

NGSS.HS-PS3-3

If the speed of an object is increasing, its (a)   energy store is increasing.

Tags

NGSS.MS-PS3-5

NGSS.MS-PS3-1

What is the acceleration of an object if a force of 10 N is applied to a mass of 2 kg?

• 5 m/s^2

• 10 m/s^2

• 20 m/s^2

• 2 m/s^2

Tags

NGSS.MS-PS2-2