Conservation of Mechanical Energy

Front

What is the principle of Conservation of Mechanical Energy?

Back

The principle states that in a closed system, the total mechanical energy (kinetic + potential) remains constant if only conservative forces are acting.

Front

Define Kinetic Energy (KE).

Back

Kinetic Energy is the energy an object possesses due to its motion, calculated as KE = 1/2 mv², where m is mass and v is velocity.

Front

Define Potential Energy (PE).

Back

Potential Energy is the energy stored in an object due to its position or configuration, commonly calculated as PE = mgh, where m is mass, g is acceleration due to gravity, and h is height.

Front

What happens to Potential Energy as an object falls?

Back

As an object falls, its Potential Energy decreases while its Kinetic Energy increases, keeping the total mechanical energy constant.

Front

At what point is Kinetic Energy highest in a free-falling object?

Back

Kinetic Energy is highest just before the object hits the ground, as all Potential Energy has been converted to Kinetic Energy.

Front

What is the total Mechanical Energy (ME) of an object?

Back

Total Mechanical Energy is the sum of Kinetic Energy and Potential Energy: ME = KE + PE.

Front

If a roller coaster car has 100 joules of Mechanical Energy at the top of a hill, what will its Mechanical Energy be at the bottom?

Back

The Mechanical Energy will still be 100 joules, assuming no energy is lost to friction or air resistance.

Front

How do you calculate the Kinetic Energy of a 2 kg object moving at 3 m/s?

Back

KE = 1/2 mv² = 1/2 (2 kg)(3 m/s)² = 9 joules.

Front

What is the Potential Energy of a 1 kg object at a height of 10 m?

Back

PE = mgh = (1 kg)(9.8 m/s²)(10 m) = 98 joules.

Front

If a ball is dropped from a height of 20 m, what is its Kinetic Energy just before it hits the ground?

Back

Assuming no energy loss, KE = PE at the top = mgh = (1 kg)(9.8 m/s²)(20 m) = 196 joules.