Energy Revision

What energy is stored in a moving object?

• Elastic potential

• Kinetic

• Gravitatinal potential

What is the main energy transfer for a long distance runner?

• Kinetic --> chemical

• chemical --> gravitational potential

• Chemical --> kinetic

Which of these cannot happen?

• Energy cannot be stored

• Energy cannot be dissipated

• Energy cannot be created

If 4000J of energy is transferred and 2500J is usefully stored, how much energy is wasted?

• 6500J

• 1500J

• 3250J

What happens to dissipated energy?

• It spreads out into the surroundings

• It disappears from the system

• It is transferred into usful stores

Which is the correct equation for Energy in the kinetic store?

What is the correct units for work done?

• Joules (J)

• Watts (W)

• Newtons (N)

Which is the correct equestion for work done?

• Work done = Force x Distance

• Work done = Force x Time

A hairdryer transformed 10,000J of energy in 4 sec. What is it's power?

• 10,000W

• 40,000W

• 2,500W

• 25,000W

What is the efficiency of Christmas lights that give out 10W of light radiation for an electrical input of 200W

• 20%

• 10%

• 5%

• 2%