Question

An 80.0 kg crate is lifted by a 1000 N upward force by the tension in the cables. What is the magnitude of the net force on the crate?

100 N
216 N
450 N
1000 N

Answer 1

We are given that a force of 1000N is being applied on the box in the upward direction

but we also know that the force of gravity is also acting on the box

We know that the force applied by gravity on an object is equal to mg

(where m is the mass of the object and g is the gravitational constant)

Finding the downward force being applied:

Force applied by gravity = mg

F = mg

replacing the variables

F = (80)(9.8)

F = 784 N

Hence, a downward force of 784 N is also being applied on the box

Net force on the Box :

net force is the final force being applied in the direction of motion

Now that we know all the forces being applied on the box, we can find the net force on the box

Net force = 1000 - 784

Net force = 216 N