Physics Energy Review

Front

What is Kinetic Energy (KE)?

Back

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

Front

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

Back

To find the speed (v) of an object from its Kinetic Energy (KE), use the formula v = sqrt(2 * KE / m), where m is the mass of the object.

Front

What is Gravitational Potential Energy (PE)?

Back

Gravitational Potential Energy is the energy an object possesses due to its height above the ground, calculated using the formula PE = mgh, where m is mass, g is acceleration due to gravity, and h is height.

Front

How do you calculate the velocity of a falling object just before it hits the ground?

Back

Use the formula v = sqrt(2gh), where g is the acceleration due to gravity (approximately 9.81 m/s²) and h is the height from which it falls.

Front

What is the relationship between Kinetic Energy and Potential Energy in a free-falling object?

Back

As an object falls, its Potential Energy decreases while its Kinetic Energy increases, conserving the total mechanical energy (PE + KE = constant) if air resistance is negligible.

Front

What is the formula for calculating Kinetic Energy?

Back

The formula for Kinetic Energy is KE = 1/2 mv², where m is the mass of the object and v is its velocity.

Front

If a 50 kg object falls from a height of 25 m, what is its velocity just before impact?

Back

The velocity just before impact is approximately 22.14 m/s, calculated using v = sqrt(2gh).

Front

How do you find the height of an object given its Gravitational Potential Energy?

Back

To find the height (h) from Gravitational Potential Energy (PE), use the formula h = PE / (mg), where m is mass and g is acceleration due to gravity.

Front

What is the Kinetic Energy of a 1000 kg car moving at 5 m/s?

Back

The Kinetic Energy of the car is 12500 J, calculated using KE = 1/2 mv².

Front

What happens to the Kinetic Energy of an object if its speed doubles?

Back

If the speed of an object doubles, its Kinetic Energy increases by a factor of four, since KE is proportional to the square of the velocity.