Mechanical Energy, Work Calculation

All of the following are examples demonstrating mechanical energy EXCEPT –

• an oven cooking food.
• a fan blowing out air. 
• a boy riding a bicycle.
• a girl writing with a pen.

gravitational potential energy is defined as

• the energy an object has due to its height above the ground
• the energy an object has due to its motion
• the energy a spring has due to its stretch
• the chemical energy stored in the molecules of atoms

You drop a 5 kg ball from a height of 2 m. Just before it reaches the ground, what type of energy does it have?

• Potential Energy
• Kinetic Energy
• Nuclear Energy
• Chemical Energy

Where does the pendulum have the greatest kinetic energy?

• A

• B

• C

• D

• E

Where does the pendulum have the least amount of potential energy?

• A

• B

• C

• D

• E

Where does the pendulum have the greatest potential energy? (pick 2)

• A

• B

• C

• D

• E

Which of the following is a true statement about work?

• It measures how quickly an object accelerates 
• It measures how much effort is applied over a certain distance
• It measures the change in an object's rate of speed
• It measures how much time it takes to move a massive object

A kid applies a force of 70 N to a ball over 1.1 meters. How much work did he do on the ball? 

• 77 J
• 7.7 J 
• 0.7 J 
• 770 J 

Tags

CCSS.7.NS.A.2A

CCSS.7.NS.A.2B

You do 90 joules of work in 30 seconds. How much power have you generated?

• 30 watts
• 3 watts
• 120 watts
• 270 watts

Which of the following would produce the most power?

• A mass of 10 kilograms lifted 10 meters in 10 seconds 
• A mass of 10 kilograms lifted 10 meters in 5 seconds
• A mass of 5 kilograms lifted 10 meters in 5 seconds
• A mass of 5 kilograms lifted 5 meters in 10 seconds