Question

In order to do work, the force vector must be

Answer 1

Question 1  

In order to do work, the force vector must be

in the same direction as the displacement vector and the motion.

Question 2  

In which of the following cases is work being done on an object?

Pulling a trailer up a hill

Question 3  

Which situation is an example of NOT doing work?

carrying a box

Question 4  

Work is measured in

Joules

Question 5  

To find the work done, the force exerted and distance moved are multiplied. A couch is moved twice before you are happy with its placement. The same force was used to move the couch both times. If more work is done the first time it is moved, what do you know about the distance it was moved?

When more work was done, the couch was moved further.

Question 6  

A weight lifter raises a 1600 N barbell to a height of 2.0 meters. How much work was done? W = Fd

3200 Joules

Question 7  

You and a friend (Alex) are at a a tree-top adventure park .. . . part of the course requires you to climb up a rope. You both climb the same rope in the same amount of time. However, the tension in the rope is greater

when Alex climbs. Who did the most work?

Alex did - more tension means more force - more force means more work was done  

Question 8  

Doing work at a faster rate creates power.

more

Question 9  

In one challenge on the Titan Games, competitors have to lift 200 pounds up a long ramp. Angel is able to move the weight in 42 seconds. Anthony gets it done in only 38 seconds. Which statement is true?

Anthony has more power than Angel.  

Question 10  

A mountain climber exerts 41,000 J of work to climb a cliff. How much power does the climber need if she wants to finish in only 500 seconds? Power = Work / time

82 Watts

Question 11  

Your family is moving to a new apartment. While lifting a box 83 Joules of work is done to put the box on a truck, you exert an upward force of 75 N for 3 s. How much power is required to do this? (Hint: You only need two of the 3 numbers given!) Power = Work / time

27.7 Watts

*100% CORRECT ANSWERS

Answer 2

As we know that total work done by a force is given by

$W = F.d$

$W = Fdcos\theta$

so it is product of force and displacement along same direction

as we can write it as

$W = (Fcos\theta)(d)$

so it must be the product of force and displacement in same directions so correct answer must be

B. in the same direction as the displacement vector and the motion.