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Investigating Forces & Motion
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Investigating Forces and Motion (1998)(Granada Learning).iso
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topic6
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question.dat
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1998-02-10
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[question1]
type:3
caption:What is the correct definition of the joule, the unit of energy?<p>
correct:6g12a
wrong1:6g12b
wrong2:6g12c
wrong3:6g12d
feedback:\
1.0 joule is the energy transferred when a force of 1.0 newton moves a \
distance of 1.0 metre in the direction of the force:<p>\
1.0 J = 1.0 N x 1.0 m.<p>
[question2]
type:2
caption:\
What is the work done by a force of 4.0 N when it moves 12 m in the \
direction of the force?<p>
correct:48 J
wrong1:3.0 J
wrong2:4.0 J
wrong3:8.0 J
feedback:\
Use the equation:<p>\
work done = force x distance<p>\
<center>= 4.0 x 12</center><p>\
<center>= 48 J.</center><p>
[question3]
type:2
caption:\
What is the increase in potential energy of a 10 N weight when it is \
raised by 2.5 m?<p>
correct:25 J
wrong1:2.5 J
wrong2:4.0 J
wrong3:250 J
feedback:\
The increase in potential energy equals the work done.<p>\
work done = force x distance<p>\
The force needed to raise the object is equal to its weight.<p>\
weight = 10 N<p>\
Thus,<p>\
increase in potential energy = force x distance<p>\
<center>= 10 x 2.5</center><p>\
<center>= 25 J.</center><p>
[question4]
type:2
caption:\
How much energy is required to raise a 20 kg mass 6.0 m above the \
surface of the Earth? (Assume <I>g</I> = 10 m/s<sup>2</sup>.)<p>
correct:1 200 J
wrong1:6.0 J
wrong2:20 J
wrong3:120 J
feedback:\
Gravitational potential energy = <I>mgh<p>\
</I><p>\
<center>= 20 x 10 x 6</center><p>\
<center>= 1 200 J.</center><p>
[question5]
type:2
caption:\
An athlete with a mass of 70 kg is running at 10 m/s. What is the \
athlete's kinetic energy?<p>
correct:3 500 J
wrong1:700 J
wrong2:350 J
wrong3:35 J
feedback:\
<I>E<SUB>k</SUB></I> = ½<I>mv</I><sup>2</sup><p>\
<center>= ½ x 70 x 10<sup>2</sup></center><p>\
<center>= 3 500 J.</center><p>
[question6]
type:2
caption:What is the kinetic energy of a 0.1 kg ball travelling at 50 m/s?<p>
correct:125 J
wrong1:5.0 J
wrong2:250 J
wrong3:2 500 J
feedback:\
<I>E<SUB>k</SUB></I> = ½<I>mv</I><sup>2</sup><p>\
<center>= ½ x 0.1 x 50<sup>2</sup></center><p>\
<center>= 125 J.</center><p>
[question7]
type:2
caption:\
A 2.0 kg rock is dropped from a 30 m cliff. What is its kinetic energy \
just before it hits the beach? (Assume <I>g</I> = 10 \
m/s<sup>2</sup>.)<p>
correct:600 J
wrong1:60 J
wrong2:300 J
wrong3:1 500 J
feedback:\
Assuming air resistance is negligible, then applying the principle of \
the conservation of energy:<p>\
final kinetic energy = initial potential energy<p>\
<I>= mgh</I><p>\
<center>= 2.0 x 10 x 30</center><p>\
<center>= 600 J.</center><p>
[question8]
type:2
caption:\
A 0.5 kg stone is thrown vertically upwards with initial kinetic \
energy of 25 J. How high does it rise? (Assume <I>g</I> = 10 \
m/s<sup>2</sup>.)<p>
correct:5.0 m
wrong1:25 m
wrong2:12.5 m
wrong3:2.5 m
feedback:\
Assuming air resistance is negligible, then applying the principle of \
the conservation of energy:<p>\
final potential energy = initial kinetic energy<p>\
<center>= 25 J</center><p>\
Also, potential energy <I>Eg</I> = <I>mgh</I>, therefore,<p>\
<img src="sa6q8a" align=center><p>\
<img src="sa6q8b" align=center><p>\
<center>= 5.0 m.</center><p>
[question9]
type:2
caption:A 20 kg mass is given 1 000 J of kinetic energy. What is its speed?<p>
correct:10 m/s
wrong1:20 m/s
wrong2:50 m/s
wrong3:500 m/s
feedback:\
<I>E<SUB>k</SUB></I> = ½<I>mv</I><sup>2</sup>, therefore,<p>\
v = <img src="sqrt">(2<I>E</I><SUB>k</SUB>/<I>m</I>)<p>\
= <img src="sqrt">(2.0 x 1 000/20)<p>\
<center>= 10 m/s.</center><p>
[question10]
type:2
caption:\
If you lift an apple with a weight of 1.0 N through a height of 1.0 m, \
how much work do you do?<p>
correct:1.0 J
wrong1:9.8 J
wrong2:10 J
wrong3:0.0 J
feedback:\
work done = force x distance<p>\
<center>= 1.0 x 1.0</center><p>\
<center>= 1.0 J.</center><p>
[question11]
type:3
caption:What is the correct definition of the watt, the unit of power?<p>
correct:6g13a
wrong1:6g13b
wrong2:6g13c
wrong3:6g13d
feedback:\
1.0 watt is the power when 1.0 joule of energy is transferred in 1.0 \
second:<p>\
in other words, <center>1W = 1J/1s</center><p>
[question12]
type:2
caption:\
An electric heater converts 2 500 J of electrical energy into heat and \
light in 5.0 s. What is the power of the heater?<p>
correct:500 W
wrong1:2 500 W
wrong2:1 000 W
wrong3:12 500 W
feedback:\
<img src="sa6q12a" align=center><p>\
<img src="sa6q12b" align=center><p>\
<center>= 500 W.</center><p>
[question13]
type:3
caption:\
How do you calculate the power from the work done and the time taken? \
Which is the correct expression?<p>
correct:6g14a
wrong1:6g14b
wrong2:6g14c
wrong3:6g14d
feedback:Power = work done ÷ time<p>
[question14]
type:2
caption:\
A cyclist is generating 600 W of power. If the cyclist works at this \
rate for 1.0 minute, how much energy is transfered from the muscles in \
use?<p>
correct:36 000 J
wrong1:600 J
wrong2:10 J
wrong3:100 J
feedback:\
Work done = power x time<p>\
<center>= 600 x 60</center><p>\
<center>= 36 000 J.</center><p>
[question15]
type:3
caption:\
Which of these graphs shows how the total energy of a falling ball \
changes with the distance fallen? (Assume that air resistance is \
negligible.)<p>
correct:6g10c
wrong1:6g10a
wrong2:6g10b
wrong3:6g10d
feedback:\
If air resistance is negligible, and no energy is lost to the \
surroundings, the total energy is constant.<p>
[question16]
type:3
caption:\
Which of these graphs shows how the potential energy of a falling ball \
changes with the distance fallen? (Assume that air resistance is \
negligible.)<p>
correct:6g10b
wrong1:6g10a
wrong2:6g10c
wrong3:6g10d
feedback:\
Gravitational potential energy is directly proportional to height \
(<I>E<SUB>g</SUB></I> = <I>mgh</I>). This means that the potential \
energy will decrease linearly (as a straight line) with distance \
fallen.<p>
[question17]
type:3
caption:\
Which of these graphs shows how the kinetic energy of a falling ball \
changes with the distance fallen? (Assume that air resistance is \
negligible.)<p>
correct:6g10a
wrong1:6g10b
wrong2:6g10c
wrong3:6g10d
feedback:\
As the potential energy decreases, so the kinetic energy increases. \
The kinetic energy of the ball will increase linearly (as a straight \
line) with distance fallen.<p>
[question18]
type:1
image:6g11
caption:\
This diagram shows the trajectory of a stone thrown from a cliff. At \
which point in its motion does it have maximum potential energy?<p>
correct:B
wrong1:A
wrong2:C
wrong3:D
feedback:\
The ball has maximum potential energy at the highest point in its \
motion.<p>
[question19]
type:1
image:6g11
caption:\
This diagram shows the trajectory of a stone thrown from a cliff. At \
which point in its motion does it have maximum kinetic energy?<p>
correct:d
wrong1:a
wrong2:b
wrong3:c
feedback:\
The stone will have maximum kinetic energy at the greatest distance \
below its highest point. This is where the maximum amount of potential \
energy will have been converted into kinetic energy.<p>
[question20]
type:2
caption:\
A stone is thrown vertically into the air. Which one of these \
statements about the energy of the stone is false?<p>
correct:The stone's kinetic energy is a maximum at its highest point.
wrong1:\
If there is no air resistance, the sum of the stone's potential energy \
and its kinetic energy is constant.
wrong2:The stone's potential energy increases as it rises.
wrong3:\
The stone's kinetic energy equals its potential energy when it reaches \
half its maximum height.
feedback:\
The false statement says that the stone's kinetic energy is greatest \
at its highest point. In fact, this is where its potential energy is \
greatest and its kinetic energy is least.<p>