Section 5.3
Force and Motion in Two Dimensions
Practice Test
1.
A 475-N trunk is resting on a plane inclined 40.0° above the horizontal. Find the components of the weight force parallel and perpendicular to the plane.
a.
F
g
x
= -364 N,
F
g
y
= -305 N
b.
F
g
x
= 364 N,
F
g
y
= 305 N
c.
F
g
x
= 305 N,
F
g
y
= 364 N
d.
F
g
x
= -305 N,
F
g
y
= -364 N
Hint
2.
A 75-kg person on skis is going down a hill sloped at 30.0°. The coefficient of kinetic friction between the skis and the snow is 0.15. How fast is the skier going 10.0 s after starting from rest?
a.
36 m/s
2
b.
36 m/s
c.
78 m/s
d.
78 m/s
2
Hint
3.
Two forces are exerted on an object. A 43-N force acts exactly at 240° and a 67-N force acts at 300°. What are the magnitude and direction of the equilibrant?
a.
96 N at 7°
b.
96 N at 97°
c.
84 N at 97°
d.
96 N at -83°
Hint
4.
A force that produces equilibrium is a(n) __________.
a.
net force
b.
resultant
c.
equilibrant
d.
constant
Hint
5.
A 175-N sign is supported in a motionless position by two ropes that each make 53.0° angles with the horizontal. What is the tension in the ropes?
a.
175 N
b.
109 N
c.
310 N
d.
146 N
Hint
6.
In Figure 5-11, if B's magnitude is 50 N and C's is 30 N, what is the magnitude of A?
a.
80 N
b.
40 N
c.
20 N
d.
58 N
Hint
7.
Two ropes pull on a ring. One exerts a 50.0-N force at 42.0°, the other a 87.0-N force at 70.0°. What is the net force on the ring?
a.
133 N at 30.0°
b.
100 N at 60.0°
c.
100 N at 56.0°
d.
133 N at 60.0°
Hint
8.
If in Figure 5-13 the skier has mass 45 kg and the slope is at 35°, what is the component of the skier's weight perpendicular to the slope?
a.
250 N
b.
440 N
c.
360 N
d.
it cannot be determined with the given information
Hint
9.
A 225-N weight has one horizontal rope exerting a force of 98.0 N on it. What are the magnitude and direction of the resultant force on the weight?
a.
2.45×10
1
N at 293°
b.
2.45×10
2
N at 343°
c.
2.45×10
2
N at 293°
d.
1.27×10
2
N at 315°
Hint
10.
If in Figure 5-13 the skier has mass 45 kg and the slope is at 35°, what is the normal force of the hill on the skier?
a.
250 N
b.
it cannot be determined with the given information
c.
440 N
d.
360 N
Hint
11.
A 225-N weight has one horizontal rope exerting a force of 98.0 N on it. What are the magnitude and direction of the force needed to put the weight into equilibrium?
a.
1.27×10
2
N at 113°
b.
2.45×10
2
N at 293°
c.
2.45×10
1
N at 113°
d.
2.45×10
2
N at 113°
Hint
12.
In Figure 5-11, if A's magnitude is 16 N and B's is 25 N, what is the magnitude of C?
a.
41 N
b.
16 N
c.
19 N
d.
30 N
Hint
13.
If in Figure 5-13 the skier has mass 45 kg and the slope is at 35°, what is the component of the skier's weight parallel to the slope?
a.
360 N
b.
440 N
c.
it cannot be determined with the given information
d.
250 N
Hint
14.
A 475-N trunk is sliding down a plane inclined 40.0° above the horizontal. Calculate the magnitude of the acceleration.
a.
62.9 m/s
2
b.
7.51 m/s
2
c.
6.29 m/s
d.
6.29 m/s
2
Hint
