Answer: 117.60N
Explanation:
Weight is a force. Therefore, we can use the force formula to find weight.

W = weight
m = mass
g = acceleration due to gravity (
)

Answer: force = mass x accelegation
Explanation: 15x3 = 45 N
Elevation would be showing you what height you are at, energy would be like what force your putting into the object.
Answer:
friction reduces the efficiency of machines, thus we must reduce the friction force that is acting upon it.