Mechanical Energy Review

Front

What is Mechanical Energy?

Back

Mechanical Energy is the sum of potential energy and kinetic energy in a system.

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 height, calculated as PE = mgh, where m is mass, g is acceleration due to gravity, and h is height.

Front

What is the formula for calculating Kinetic Energy?

Back

KE = 1/2 mv².

Front

What is the formula for calculating Potential Energy?

Back

PE = mgh.

Front

If a car has 10 J of Potential Energy at the bottom of a hill, what is its Kinetic Energy?

Back

90 joules (Total Mechanical Energy is conserved).

Front

How do you calculate the speed of an object using Kinetic Energy?

Back

Rearranging KE = 1/2 mv² gives v = sqrt(2KE/m).

Front

What happens to Potential Energy as an object falls?

Back

As an object falls, its Potential Energy decreases while its Kinetic Energy increases.

Front

What is the Kinetic Energy of a 0.143 kg baseball traveling at 41.1 m/s?

Back

120.8 joules.

Front

What is the Potential Energy of a 1.0 kg ball at the top of a 10.0 m hill?

Back

98 joules (PE = mgh = 1.0 kg * 9.8 m/s² * 10.0 m).