Aljalal-Phys101-Oct 2007-Ch5-page 1
Questions
Chapter 5
Force and Motion - I
5-1 Force
5-2 Some Particular Forces
5-3 Mass
5-4 Newton's Second Law
5-5 Newton's First Law
5-6 Newton's Third Law
5-7 Applying Newton's Laws
Aljalal-Phys101-Oct 2007-Ch5-page 2
5-3 Mass
M1-041
The weight of an astronaut on Earth is 800 N. What is his
weight on planet Mars, where g = 3.76 m/s2?
A) 135 N
B) 213 N
C) 930 N
D) 307 N
E) 800 N
Answer D
Aljalal-Phys101-Oct 2007-Ch5-page 3
5-4 Newton's Second Law
M1-062
A 2.00-kg mass is hanging from the ceiling of an elevator
accelerating upward at a = 2.50 m/s2 (see Fig. 6). What is the
tension T in the string?
A) 24.6 N
B) 19.8 N
C) 27.7 N
D) 33.4 N
E) 5.50 N
Answer A
Aljalal-Phys101-Oct 2007-Ch5-page 4
5-4 Newton's Second Law
M1-061
A 4.0 kg block is pushed upward a 30° inclined frictionless
plane with a constant horizontal force F (Fig 4). If the block
moves with a constant speed find the magnitude of the force
F.
A) 40 N
B) 33 N
C) 23 N
D) 0 N
E) 9.8 N
Answer C
Aljalal-Phys101-Oct 2007-Ch5-page 5
5-4 Newton's Second Law
M1-061
An elevator cab with a total mass of 2000 kg is pulled
upward by a cable. If the elevator accelerates at 2.00 m/s2
upward, find the tension in the cable.
A) 0.00 N
B) 3.25 ×104 N
C) 1.56 ×104 N
D) 2.36 ×104 N
E) 9.80 N
Answer D
Aljalal-Phys101-Oct 2007-Ch5-page 6
5-4 Newton's Second Law
M1-042
Acceleration is always in the direction:
A) of the final velocity.
B) of the initial velocity .
C) of the net force .
D) of the displacement.
E) opposite to the frictional force.
Answer C
Aljalal-Phys101-Oct 2007-Ch5-page 7
5-4 Newton's Second Law
M1-041
A 20.0 kg block is resting on a frictionless horizontal table. A
horizontal string pulls the block. If the tension in the string is
20.0 N, what is the speed of the block after moving 2.0 m?
A) 2.0 m/s
B) 4.0 m/s
C) 1.0 m/s
D) 3.0 m/s
E) 5.0 m/s
Answer A
Aljalal-Phys101-Oct 2007-Ch5-page 8
5-7 Applying Newton's Laws
M1-062
Two blocks of masses m1 = 4.00 kg and m2 = 2.00 kg are
connected by a string passing over a massless and
frictionless pulley and placed on a frictionless horizontal table
as shown in Fig. 3. A force of F = 10.0 N at an angle of 60.0°
with the horizontal is applied to m1. The magnitude of
acceleration of the system is:
A) 3.27 m/s2
B) 9.80 m/s2
C) 2.43 m/s2
D) 10.84 m/s2
E) 1.36 m/s2
Answer C
Aljalal-Phys101-Oct 2007-Ch5-page 9
5-7 Applying Newton's Laws
M1-062
Two boxes A and B (mA = 3.0 kg and mB =1.0 kg) are in
contact on a horizontal frictionless surface and move along
the x-axis (see Fig. 4). A horizontal force F = 10.0 i N is
applied on Box A. The net force acting on A is F1 and on B is
F2. Which one of the following statements is correct?
A) F1 = 5.0 i N and F2 = -5.0 i N
B) F1 = 7.5 i N and F2 = 2.5 i N
C) F1 = 2.5 i N and F2 = 7.5 i N
D) F1 = 0 N and F2 = 0 N
E) F1 = 2.5 i N and F2 = - 2.5 i N
Answer B
Aljalal-Phys101-Oct 2007-Ch5-page 10
5-7 Applying Newton's Laws
M1-062
Two boxes, one of mass m = 5.00 kg and the other with an
unknown mass M are connected with a string passing over a
massless frictionless pulley and are placed on frictionless
planes as shown in Fig. 5. What must be the mass M, if it
goes down the plane with an acceleration of a = 2.45 m/s2?
A) 2.50 kg
B) 8.70 kg
C) 13.5 kg
D) 19.1 kg
E) 10.0 kg
Answer D
Aljalal-Phys101-Oct 2007-Ch5-page 11
5-7 Applying Newton's Laws
M1-061
To measure your weight, you stand on a spring scale on the
floor of an elevator. Among the following situations, select the
one that gives the highest reading on the scale:
A) The elevator moves downward at constant speed.
B) The elevator moves upward with decreasing speed.
C) The elevator remains stationary.
D) The elevator moves downward with increasing speed.
E) The elevator moves upward with increasing speed.
Answer E
Aljalal-Phys101-Oct 2007-Ch5-page 12
5-7 Applying Newton's Laws
M1-061
A 7.0 kg block and a 3.0 kg block are connected by a string
as shown in Fig 5. If the pulley is massless and the surface is
frictionless, the magnitude of the acceleration of the 3.0 kg
block is:
A) 6.7 m/s2
B) 3.3 m/s2
C) 4.9 m/s2
D) 2.9 m/s2
E) 9.8 m/s2
Answer D
Aljalal-Phys101-Oct 2007-Ch5-page 13
5-7 Applying Newton's Laws
M1-042
Two blocks are in contact on a frictionless table . A horizontal
force is applied to block (m2), as shown in Fig. 4. If m1=3.0
kg, m2=2.0 kg, and F=5.0 N, find the magnitude of the force
between the two blocks.
A) 4.7 N
B) 2.0 N
C) 4.0 N
D) 5.0 N
E) 3.0 N
Answer E
Aljalal-Phys101-Oct 2007-Ch5-page 14
5-7 Applying Newton's Laws
M1-041
A 2.0 kg box slides down a frictionless vertical wall while you
push on it with a force F at a 30 degrees angle with the
vertical (see Fig 3). What is the magnitude of the normal
force of the wall on the box if it is to slide down at a constant
speed?
A) zero N
B) 5.67 N
C) 15.6 N
D) 2.56 N
E) 11.3 N
Answer E
Aljalal-Phys101-Oct 2007-Ch5-page 15
5-7 Applying Newton's Laws
M1-041
Two masses m1 (= 2.0 kg) and m2 (= 3.0 kg) are connected
as shown in Fig 4. Find the tension T2 if the tension T1 =
50.0 N.
A) zero
B) 50.0 N
C) 20.0 N
D) 30.0 N
E) 10.0 N
Answer D
