Question

A person removes a 8.45 kg object from a shelf that is 1.82 m above the floor. They lower the item at a constant velocity to another shelf that is 0.835 m above the floor. What is the work done by the person on the object?

Answer 1

81.6 J

Step-by-step explanation:

let the acceleration due to gravity = 9.8 m/s/s

W = F • s

F = newtons of force

s = distance travelled

the force to carry a mass is equal to mass multiplied by the acceleration due to gravity. This is confirmed using Sir Issac Newtons second and third law stating that the force of an object is equal to its mass multiplied by its acceleration (F = m • a) and that every action has an equal and opposite reaction, respectively. This means that the force of the object is equal to 8.45kg • 9.8 m/s/s, or 82.81 newtons of force.

F = 82.81 N

To find the distance displaced, you simply subtract 0.835m from 1.82m, giving a value of 0.985m.

s = 0.985m

Finally, in order to find work, you multiply 82.81 N by 0.985m resulting in a work equal to 81.6 J, after being rounded due to match the significant digits of the question.