Question

15 points for 2 questions

1. your family is moving to a new home. While lifting a box 1.5m straight up to put it on a truck, you exert an upward force of 200N. Calculate the amount of work you did.

A) 133J

B) 198.5J

C) 201.5J

D) 300J


2. A truck pulls a trailer at a constant velocity for a 100m while exerting a force of 480N. Calculate the work done.

A) 4.8J

B) 380J

C) 48,000J

D) 580J

Answer 1

I believe the answer would be c because i think that you multiply the 2

Answer 2

1. D) 300 J

The work done by a constant force is given by:

$W=Fdcos \theta$

where F is the force applied, d is the distance, and $\theta$ is the angle between the direction of the force and the direction of motion.

In this problem, F=200 N, d=1.5 m while $\theta=0^{\circ}$, because the force is parallel to the motion of the box, therefore the work done is

$W=(200 N)(1.5 m)(cos 0^{\circ})=300 J$

2. C) 48,000 J

We can use the same formula used in the previous part of the problem:

$W=Fdcos \theta$

In this case:

F=480 N

d=100 m

$\theta=0^{\circ}$

So the work done is

$W=(480 N)(100 m)(cos 0)=48,000 J$