Kinetic energy and potential energy

Question 1

Define Kinetic Energy, then state the equation associated with it.

Answer 1

Kinetic energy is the energy of an object ude to its motion.

E_{k =}1/2 mv²

Kinetic Energy = half x mass x Velocity²

Question 2

Define PotentialEnergy, then *state *the equation associated with it.

Answer 2

Potential energy is the energy of an object due to it’s position.

E_p= mgh

Energy = Force x Height change

Question 3

What is the relationship between Potential Energy and Kinetic Energy with air resistance and without air resistance.

Answer 3

In an ideal world that has no air resistance.

mgh = 1/2 mv²

Potential Energy = Kinetic Energy

    In a world with air resistance.

mgh > 1/2 mv2

Potential Energy > Kinetic Energy

Question 4

A truck of mass 2000kg is moving at a speed of 30ms^-1 what is it’s kinetic energy.

Answer 4

E_k = 1/2 mv²

1/2 x 2000 x 30²= 900000J

Question 5

Air resistance slows down objects kinetic energy we can calulate the fritional force.

An object of 10kg falls 20 m on earth. It’s kinetic energy is 1900J what is the frictional force.

Answer 5

10 x 20 x 9.81 = 1962J

1962 - 1900 = 62J