Question

1.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?
Angel has more power than Anthony.


Angel does more work than Anthony.


Anthony does more work than Angel.


Anthony has more power than Angel.



2.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

20,500,000 Watts


82 Watts


0.0122 Watts


41,500 Watts



3.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



249 Watts


25 Watts


2075 Watts


27.7 Watts

Answer 1

Answer:

For 1: The correct statement is Anthony has more power than Angel.

For 2: The correct answer is 82 Watts.

For 3: The correct answer is 27.7 Watts.

Explanation:

• For 1:

Work done is defined as the product of force and displacement.

Power is defined as the amount of work done in a given time.

$\text{Power}=\frac{\text{Work done}}{\text{Time taken}}$

As, both the players are carrying same amount of weight and for the same distance, therefore the work done by both the players remains the same.

But the time taken by Anthony is 38 seconds which is less than the Angel whose time was 42 seconds.

As, power is inversely proportional to the time taken, So more the time taken, less will be the power and vice-versa.

Therefore, the correct statement is Anthony has more power than Angel.

• For 2:

Power is defined as the amount of work done in a given time.

$\text{Power}=\frac{\text{Work done}}{\text{Time taken}}$

We are given:

Work done = 41000 J

Time taken = 500 seconds

Power = ? W

Putting values in above equation, we get:

$\text{Power}=\frac{41000J}{500s}=82Watts$

Hence, the correct answer is 82 Watts.

• For 3:

Power is defined as the amount of work done in a given time.

$\text{Power}=\frac{\text{Work done}}{\text{Time taken}}$

We are given:

Work done = 83 J

Time taken = 3 seconds

Power = ? W

Putting values in above equation, we get:

$\text{Power}=\frac{83J}{3s}=27.66Watts\approx 27.7W$

Hence, the correct answer is 27.7 Watts.

Answer 2

#1).  Anthony does the same amount of work as Angel, with more power.

#2). Power = (Work)/(Time) = 41,000 J / 500 s  =  82 watts .

#3). Power = (Work) / (Time) = 83 J / 3 sec = 27.7 watts