Gravitational Potential Energy: Definition and Calculation

This lecture covers gravitational potential energy, explaining its definition and how to calculate changes in it. The presentation includes examples of lifting and lowering objects, such as a book and a football, to demonstrate the application of the gravitational potential energy formula. The lecture concludes with a summary of the key concepts discussed.

What is the primary factor that must be overcome to lift an object vertically?

• Magnetic force

• Air resistance

• Friction

• Weight due to gravity

Which equation is used to calculate gravitational potential energy?

• Ep = mgh

• W = Fd

• F = ma

• E = mc^2

If a 1 kg object is lifted 1 meter in a gravitational field of 9.8 N/kg, what is the change in its potential energy?

• 1 joule

• 9.8 joules

• 19.6 joules

• 0.98 joules

How much does the gravitational potential energy of a 1.2 kg book increase when lifted 1.5 meters?

• 12 joules

• 15 joules

• 17.64 joules

• 9.8 joules

What is the change in gravitational potential energy when a book is lowered from 1.5 meters to 0.8 meters?

• 9.8 joules

• -8.232 joules

• -9.8 joules

• 8.232 joules

A football gains 100 joules of potential energy when kicked upwards. What is its mass if the gravitational field strength is 9.8 N/kg?

• 0.25 kg

• 2 kg

• 1 kg

• 0.5 kg

To what height is a 0.5 kg football kicked if its potential energy increases by 100 joules?

• 25.5 meters

• 15.3 meters

• 20.4 meters

• 10.2 meters