9.15 Summative assessment PS

What are the two types of mechanical energy?

• Kinetic and potential energy

• Kinetic and nuclear energy

• Potential and chemical energy

• Thermal and kinetic energy

The bike that Jeff's mom is riding uses a generator to convert ____ energy to ____ energy.

• Solar, mechanical

• Mechanical (motion), electrical

• Heat, steam

• Hydro, electrical

A skydiver jumps from a plane and is halfway through her descent. At this point in time, she has:

• Kinetic energy

• Gravitational potential energy

• Both kinetic and gravitational potential energy

• She has no energy

Between a bowling ball and a soccer ball, which one has more kinetic energy and why?

• A bowling ball because it has more mass.

• A bowling ball because it is smaller.

• A soccer ball because it has more mass.

• A soccer ball because it is smaller.

Which of the following has the GREATEST impact on the kinetic energy of an object and why?

• Mass because really small and really large objects cannot have the same kinetic energy.

• Velocity because it is squared in the formula for KE.

• Height because it can be a large amount.

A pendulum bob swings back and forth (like on a grandfather clock). Its kinetic energy and its potential energy in relation to the bottom of its swing are the same at _________________.

• 1. The bottom

• 1. One-quarter of the vertical distance between the bottom and

     top of the swing

• One-half of the vertical distance between the bottom and the

  top of the swing

• At the top of the swing

Which of the following objects has the most kinetic energy?

• A 20 kg toddler running at 5 m/s

• A 50 kg toddler running at 30 m/s

• A 90 kg toddler running at 30 m/s

• A 100 kg toddler running at 2 m/s

Gravitational potential energy depends on the ____ and ____ of the object.

• A. Friction and movement

• B. Mass and movement

• C. Height and friction

• D. Height and mass

An Olympic high jumper, with a mass of 82 kg, has a maximum gravitational potential energy of 1970 J. How high was the jump?

• A. 24 m

• B. 161.540 m

• C. 2.5 m

• D. 201 m

The world record for pole vaulting is 6.15 m. If the pole vaulter's gravitational potential energy is 4942 J, what is his mass?

• A. 803.6 kg

• B. 504.3 kg

• C. 30,393.3 kg

• D. 82 kg