Question

which has more kinetic energy, a 5-kg object moving at 5 m/s 1 m off the ground or a 5-kg object at rest 2 m off the ground?

Answer 1

The moving object has kinetic energy with the object at rest having potential energy.

Answer 2

Step-by-step explanation:

Kinetic energy is the energy due to changes in position of a body. It is always with regards to motion of a body.

Potential energy on the other hand is the energy at rest of a body.

To estimate kinetic energy, we use the formula:

K.E =
`(1)/(2)m v^(2)`

where m is the mass of the body and v is the velocity of the object.

mass is 5kg and velocity is 5ms⁻¹

K.E =
`(1)/(2)5 x  5^(2)`

K.E = 62.5J

for the object at rest;

potential energy is calculated:

P.E = mgh

where m is the mass, g is the acceleration due to gravity and h is the height

m is 5kg, h is 2 and g is 9.8

P.E = 5 x 9.8 x 2 = 98J

The moving object has kinetic energy with the object at rest having potential energy.