Physics 2204 – Unit 2 Test 1 – Forces and Newton’s Laws 2008 - 09
Part I – Multiple Choice. Place the letter corresponding to the best answer on page 4 of this test.
1.
What is the weight of a block of iron which has a mass of 5.0 kg on Earth?
(A)
2.
5.0 N
(D)
49 N
electrical
strong nuclear
(B)
(D)
gravitational
weak nuclear
(B)
(C)
(D)
A force of 100 N acts at an angle of 30o with the horizontal. What is the vertical component?
10 N
(B)
30 N
(C)
50 N
(D)
90 N
A force of 250 N is acting on a 50.0 kg object. If the force is directed upwards at an angle of 42o to the horizontal,
what is the effective weight of the object or its Fnormal?
(A)
7.
(C)
Which choice shows the net force of the two forces in the picture at the right?
(A)
6.
2.0 N
Your mass would be the same and weight would be one-half as much.
Your mass would be the same and weight would be twice as much.
Your mass would be one-half as much and weight would be the same.
Your mass and weight would both be one-half as much.
(A)
5.
(B)
Which category includes types of mechanical forces, such as elastic force, compression force, friction, and
push/pull forces?
(A)
(C)
4.
0.51 N
Suppose that you were transported to a planet where the value of g was double the value here on Earth.
Which statement would be correct?
(A)
(B)
(C)
(D)
3.
(20 marks)
170 N
(B)
320 N
(C)
490 N
(D)
660 N
An arrow is projected into the air at an angle of 50.0° above the ground. If the bow provides a force of 250 N to the
arrow, calculate the horizontal component of the force.
(A)
Physics 2204
130 N
(B)
160 N
(C)
Unit 2 Test 1 – Forces and Newton’s Laws
190 N
(D)
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390 N
Page 1 of 6
8.
A man pushes with a force F on the handle of a lawnmower as
shown. The angle between the handle and the horizontal is
45o. When this force is resolved into horizontal and vertical
components, how do the magnitude of the components
compare?
(A)
(B)
(C)
(D)
9.
Each component is greater than F.
Each component is less than F.
The horizontal component is greater than the vertical.
The vertical component is greater than the horizontal.
6N
What is the magnitude of the unbalanced force on the block?
(A)
(B)
(C)
(D)
3N
0N
4N
12N
24 N
5N
1N
9N
10.
What is the direction of the net force on the hoop in the diagram below?
(A)
(B)
(C)
(D)
[35o E of S]
[35o E of N]
[35o S of E]
[35o N of E]
7.0 N
10.0 N
11.
Which of the following would be a non-inertial frame of reference if you were at that location?
(A)
(B)
(C)
(D)
12.
What physical principle is demonstrated when a person’s head snaps backward as a rear end collision occurs?
(A)
(C)
13.
In a stationary elevator
In an elevator undergoing free-fall
On a train travelling North at 30 m/s
In a balloon ascending at a constant velocity
Newton’s 1st Law
Newton’s 3rd Law
(B)
(D)
Newton’s 2nd Law
Law of Equilibrant Forces
If water friction accounts for 400 N of force, what will be the acceleration of a 200 kg canoe with an engine
providing 1000 N of force?
(A)
Physics 2204
5.0 m/s2
(B)
3.0 m/s2
(C)
Unit 2 Test 1 – Forces and Newton’s Laws
10.0 m/s2
(D)
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7.0 m/s2
Page 2 of 6
14.
A tractor trailer is capable of supplying a constant force to a load. By what factor will the acceleration of the tractor
trailer change if its mass is doubled?
(A)
(C)
15.
a factor of one-half
a factor of four
(B)
(D)
a factor of two
acceleration remains constant
Which of the following statements best describes Newton’s Second Law of Motion?
(A)
(B)
(C)
(D)
Acceleration is inversely proportional to the applied force when mass is constant.
Acceleration is directly proportional to the applied force when mass is constant.
Acceleration is directly proportional to the object’s mass when the force is constant.
Both B and C are correct.
16. If the rockets shown below all start from rest, and air resistance is ignored, which one will experience the greatest
acceleration?
A)
100 N
17.
200 kg
- 2.5 m/s
2.5 m/s
(B)
(D)
100 N
300 kg
400 N
50 kg
V = 2.5 m/s
35 N
35 N
0 m/s
7 m/s
0.33 kg
(B)
3.0 kg
(C)
11 kg
(D)
Find the horizontal acceleration of the cart in the picture below
(assume there is no friction and 2 sig. digits).
(A)
(C)
20.
500 N
D)
The frictional force acting on a cart is 25 N. What is the mass of the cart if a horizontally-applied force of 40.0 N
results in an acceleration of 5.0 m/s2?
(A)
19.
100 kg
C)
The cart in the picture is moving on a horizontal surface, experiencing
an applied force of 35 N and friction force of 35 N. At the instant
shown its speed is 2.5 m/s. What will be its speed 5.0 s later?
(A)
(C)
18.
B)
0 m/s2
1.7 m/s2
(B)
(D)
13 kg
F = 110 N
o
1.0 m/s2
2.0 m/s2
30
55 kg
A horizontal force of 100.0 N is applied to a 7.8 kg box and results in an acceleration of 5.5 m/s2 [Right]. What is
the coeffiecient of kinetic friction for the surface?
(A)
Physics 2204
0.43
(B)
0.57
(C)
Unit 2 Test 1 – Forces and Newton’s Laws
0.75
(D)
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1.3
Page 3 of 6
Physics 2204 – Unit 2 Test 1 – Forces and Newton’s Laws 2008 - 09
Name: _________________________________________
School: ____________________________________
Answers to Part I – Multiple Choice – Print Your Choice Clearly
1.______
2.______
3.______
4.______
5.______
6.______
7.______
8.______
9.______
10.______
11._____
12._____
13.______
14.______
15.______
16._____
17._____
18.______
19.______
20.______
Part II – Constructed Response. Answer all questions in the space provided.
{4}
21.
Physics 2204
(Total 15 marks)
Two small farm tractors are attempting to pull a stump from the ground. One tractor pulls with a force
of 1500 N [20.0 o East of North] and the other pulls with a force of 2500 N [10.0 o North of East].
Determine the net force (with direction) that is a result of the two forces exerted by the tractors on the
stump.
Unit 2 Test 1 – Forces and Newton’s Laws
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Page 4 of 6
{3}
22.
A rope attached to a 18 kg toboggan makes an angle of 30.0 o with the ground and is pulled with a force
of 110 N. The frictional force along the snow is 40.0 N. What acceleration will the toboggan experience?
{4}
23.
In the picture the rocket is tilted at an angle of 30.0° with the horizontal. The rocket exerts a force
of 28.0 N on the 1.20 kg cart. The cart experiences a friction force of 5.00 N as it scoots along the level
surface. If the cart started from rest, what will be its speed after 2.00 s?
F = 28.0 N
30
o
1.2 kg
Physics 2204
Unit 2 Test 1 – Forces and Newton’s Laws
Merry Christmas
Page 5 of 6
{4}
24.
Do ONE PART of this question – (a) OR (b).
(a)
A horizontally applied force of 37.0 N acts on a cart for 5.00 s. During that time the speed of the cart
increases from 3.20 m/s to 8.40 m/s. If friction forces amount to 15.0 N, what is the mass of the cart?
(b)
A car having a mass of 1700 kg applies its brakes and skids to a stop in 55 m. If the initial speed was
24 m/s, what was the coefficient of kinetic friction between the tires and the road?
Physics 2204
Unit 2 Test 1 – Forces and Newton’s Laws
Merry Christmas
Page 6 of 6
Useful Formulas
Kinematics
dtot
ttot
g = −9.81 m/s 2
Vav =
a=
d = V1t + 12 at 2
2ad = V22 − V12
V2 − V1
t
d=
V1 + V2
t
2
Dynamics
Felastic = k Δx
F fr = μFN
Fun = ma
p = mv
Ft = mΔv
p = p'
FA on B = − FB on A
Work, Power and Energy
W
t
W = Fd
W = Fd cos θ
P=
PEgrav = mgh
PEelastic = 12 kx 2
KE = 12 mv 2
Wout
Win
Fd = 12 mv 2
Fd = 12 mv 2f − 12 mvi2
e=
Waves
T=
1
f
vsound = 332 + 0.6T
n=
sin i
sin r
f =
1
T
f '=
v= fλ
f
⎛
v ⎞
⎜1 −
⎟
⎝ vsound ⎠
n1 sin i = n2 sin r
f '=
v=
f
⎛
v ⎞
⎜1 +
⎟
⎝ vsound ⎠
sin θ =
mλ
d
λ
T