Question

The wattage of speaker describes the rate at which energy is converted from electrical energy to sound energy. This is the description of which of these?

A) Energy

B) Power

C) Transformation

D) Work


A bodybuilder lifts a certain weight up and down. If the body builder does it in less time, which of these statements is most accurate?

A) The body builder uses both the same energy and power.

B) The body builder uses both more energy and more power.

C) The body builder uses the same energy and but more power.

D) The body builder uses the same power and but more energy.



Students in a physical education class practiced rope climbing. Students gripped a rope that hung from the ceiling and lifted themselves up the rope using only their arms. What must be measured to determine the power output of the climbers?

A) tension on the rope and the final height

B) body mass, final height, and the tension on the rope

C) tension on the rope and the time required to complete the climb

D) body mass, final height, and the time required to complete the climb


Ocean waves travel in to the beach at an average velocity of 2.5
m/s
. If these waves come in 4 seconds apart, what is the average distance between the wave peaks, considering the formula V=d/t
?
A) 0.625 m
B) 1.6 m
C) 5.0 m
D) 10.0 m

Answer 1

a 1) c 2) b 3) d 4) is the correct answer

Answer 2

Explanation :

(A) The wattage of the speaker describes the rate at which energy is converted from electrical energy to sound energy. This shows the conversion of energy from one form to another.

So, the correct option is (C) Transformation.

(B) A bodybuilder lifts a certain weight up and down. Work is done in this case. We know that energy is the capacity to do work and power is defined as the rate of doing work.

So, the correct option is (B) "The bodybuilder uses both more energy and more power".

(C) In this case, students gripped a rope that hung from the ceiling and lifted themselves up the rope using only their arms. Power is given as :

$P=\dfrac{W}{t}=\dfrac{mgh}{t}$

Where W is the work done.

So, to determine the power output of the climber it is required to measure the mass, final height and time required.

So, the correct option is (D) " body mass, final height, and the time required to complete the climb ".

(D) Average velocity, v = 2.5 m/s

time taken, t = 4 s

$\because v=\dfrac{d}{t}$

$d=2.5\ m/s\times 4\ s$

So, d = 10.0 m

Hence, the correct option is (D).