Physics 105

Chapter 4: Dynamics: Newton's Laws of motion

Which of the following statements is WRONG?

A) While mass is a scalar quantity, weight is a vector quantity.

B) The action force and the reaction force can never act on the same object.

C) An object can move at constant velocity if only one force acts on it.

D) If an object is moving at constant velocity, then the resultant force acting on it is zero.&nbsp;

E) The acceleration is always along the direction of the resultant force.&nbsp;

In the figure the force F = 40N, M = 4kg , θ = 30° and the coefficient of kinetic friction between the ground and the block is μk = 0.2, The acceleration of the block :
<img src="https://gateway.medhemmeh.com/downloads/672f74b68064fe3f83d67cf1/bio7b47rsx" width="718" height="582"/>

In the figure , M1 =3kg ,M2 =5kg and θ=30°. All the surfaces are friction less . The acceleration (in m/s2) of mass M2 is:
<img src="https://gateway.medhemmeh.com/downloads/672f74b68064fe3f83d67cf1/j4xndtwq4i" width="665" height="582"/>

A) 0.6 up the incline

B) 0.6 down the incline

C) 2.5 up the incline

D) 2.5 down the incline

In the figure, all surfaces are rough, M1 =3 kg and M2 = 1 kg and the coefficient of friction μs = 0.5 and μk = 0.2 for all surfaces. Find the maximum value of mass m (in kg) such that mass M2 will move with mass M1 without sliding. Ignore masses of all strings and the mass of the pulley.
<img src="https://gateway.medhemmeh.com/downloads/672f74b68064fe3f83d67cf1/ti8lpaz3bp" width="760" height="546"/>

A 12 kg child is sitting on the back seat of a car that is moving at a constant velocity of 10m/s along a horizontal road. The driver notices a red traffic light ahead of him and applies the breaks, If the car comes to a stop in 12m, calculate the minimum value of the coefficient of static friction such that the child does not slide. (Assume only the force of friction acts on the child in the horizontal direction).
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A block ps mass M=6.0 KG, is in contact with another block of mass m=4.0 kg on rough horizontal surface . the coefficient of kinetic friction Mk =0.2 , and a force F=25N is applied as shown in the figure . what is the magnitude of the force ( in N) of block M on the smaller block m?
<img src="https://gateway.medhemmeh.com/downloads/672f74b68064fe3f83d67cf1/yfdab9gt9b" width="765" height="349"/>

In the figure mass m=2kg and the coefficients of friction&nbsp;
Mk =0.2 &nbsp;and Ms=0.4, the acceleration in m/s^2 of the mass m is :
<img src="https://gateway.medhemmeh.com/downloads/672f74b68064fe3f83d67cf1/7qbzca6vkk" width="669" height="591"/>

8) In the figure , Mk =0.10 and m1=4.0 kg and
m2=2.0 kg. As m2 is moving down, the acceleration of the system in m/s^2 is:
<img src="https://gateway.medhemmeh.com/downloads/672f74b68064fe3f83d67cf1/d9enn2og2g"/>

The figure shows a horizontal frictionless surface, and the mass M=4 kg and m=2 kg, the coefficient of static and kinetic friction between surfaces of blocks M and m is Mk=0.2 and Ms=0.4 .then the maximum allowed force F( in N) such that the block m does not slide is:
<img src="https://gateway.medhemmeh.com/downloads/672f74b68064fe3f83d67cf1/r9lk9whq1q" width="631" height="443"/>

D) 23.5

A box of mass M=50 kg is suspended by two massless cables as shown in the below.
Find the tension in the cable on the left:
<img src="https://gateway.medhemmeh.com/downloads/672f74b68064fe3f83d67cf1/57cdsuesg2" width="1478" height="533"/>

Two blocks of masses m1= 3.0 kg m and m2= 14 kg are Sitting of the floor of container as shown. If the container is accelerating downward at 3.5 m/s^2, then the magnitude of the force of the block m1 on m2 is ( in N):
<img src="https://gateway.medhemmeh.com/downloads/672f74b68064fe3f83d67cf1/0k4szibw2j" width="580" height="491"/>

a) 19

b) &nbsp;29

&nbsp;&nbsp;c) 49

d) &nbsp;35

mass M= 10 kg , m=4 kg , Mk between the inclined surface and the mass m is equal 0.3
If the mass m is moved above the inclined plane, determine the acceleration of the system in m/s^2:
<img src="https://gateway.medhemmeh.com/downloads/672f74b68064fe3f83d67cf1/agrfita201" width="726" height="436"/>

In this figure there is two masses connected by robe . all surfaces are frectionless. The mass M=2 kg, if the force F=40 N .
Then the value of tension T ( in N ) in the rope between the two blocks M,2M:
<img src="https://gateway.medhemmeh.com/downloads/672f74b68064fe3f83d67cf1/s2n3aezz45" width="761" height="196"/>

The inclined surface in figure is rough with Ms=0.4 &nbsp;, Mk=0.1 , if mass M =2 kg , which of following is correct :
<img src="https://gateway.medhemmeh.com/downloads/672f74b68064fe3f83d67cf1/gdzwme956m" width="774" height="507"/>

a)the box accelerate down the incline at 3.4m/s^2

b) the box accelerate down the incline at 2.4m/s^2

c) the box accelerate down the incline at 1.6 m/s^2

d) the box move down at constant velocity

e)remain static at rest&nbsp;

In the figure shown , the mass M=4 kg, and&nbsp;
M=2 kg , the coefficient of static friction between
The two masses is Ms=0.2 . Assume that there is no friction between the mass M and the floor .&nbsp;
The maximum force F that is allowed to applied , such mass m is moving with the mass M without sliding is :
<img src="https://gateway.medhemmeh.com/downloads/672f74b68064fe3f83d67cf1/pehidvwx3j" width="659" height="387"/>

A book I placed on chair on ground , then video device placed on the book .
The ground exerts a vertival force on:

c)video device only&nbsp;

d)it affects the chair , book ,and video device

&nbsp;Two bodies , the first with mass M and the second with mass m are affected by force F. If the acceleration of the second body is three times the acceleration of the first one, then the mass of the second body is:

The figure shows the force Fx that act on
21-kg mass move along the x axis. The mass begins from origin with initial velocity of&nbsp;3m/s.
Its final velocity( in m/s) at x=10m is :
<img src="https://gateway.medhemmeh.com/downloads/672f74b68064fe3f83d67cf1/dv1e0fkdb3" width="690" height="498"/>

A massive box (19kg) slides on a horizontal surface with an initial speed. The coefficient of kinetic friction between the block and the surface is 0.2. The block travels a distance of 35 m before if stops. The initial speed (in m/s) of the block is:

A block of mass M = 6.00 kg is in contact with another block of mass m = 4.00 kg on a frictionless surface, as shown in the Figure. The M block is being pushed by a 20.0-N force toward the m block. What is the magnitude of the force of the M block on the m block?
<img src="https://gateway.medhemmeh.com/downloads/672f74b68064fe3f83d67cf1/mn4wfoxnkp" width="246" height="136"/>

Two blocks connected by a string are pulled across a horizontal surface by a force applied to one of the blocks, as shown. The coefficient of kinetic friction between the blocks and the surface is 0.25. If each block has an acceleration of 2.0 m/s2 to the right, what is the magnitude F of the applied force?
<img src="https://gateway.medhemmeh.com/downloads/672f74b68064fe3f83d67cf1/7hd3eb6v80" width="756" height="434"/>

In the figure the coefficient of kinetic friction between the mass m1 and the horizontal surface is μk = 0.10 and m1 = 6.0 kg, m2 = 2.0 kg. The acceleration of the system (in m/s2) is:
<img src="https://gateway.medhemmeh.com/downloads/672f74b68064fe3f83d67cf1/n7xury37hg" width="579" height="369"/>

A) 2.45

In the figure shown, the coefficient of static friction between the mass M and the vertical wall is μs = 0.20. Given that M = 2.0 kg, determine the minimum value of the horizontal force F required to keep the mass M stationary.
<img src="https://gateway.medhemmeh.com/downloads/672f74b68064fe3f83d67cf1/hux7leczr0" width="246" height="184"/>

A 2-kg object is held stationary on a wall by a horizontal force F as shown. The static coefficient of friction between the object and the wall is 0.5. What is the minimum force required to hold the object from sliding down?
<img src="https://gateway.medhemmeh.com/downloads/672f74b68064fe3f83d67cf1/ztsd5uuq1w" width="185" height="262"/>

A horizontal, 50 N force acts on a 15-kg block on an inclined plane making an angle of 30° with the horizontal as shown in the figure. If the block slides down the plane at a constant speed, what is the coefficient of kinetic friction between the block and the surface?
<img src="https://gateway.medhemmeh.com/downloads/672f74b68064fe3f83d67cf1/at0wrzfx4r" width="264" height="151"/>

A 5.1-kg box is held at rest by two ropes that form 0-30° angles with the vertical. An external force F acts vertically downward on the box. The force exerted by each of the two ropes is denoted by T. A force diagram, showing the four forces that act on the box in equilibrium, is shown below. The magnitude of force F is 920 N. The magnitude of force T is equal to:
<img src="https://gateway.medhemmeh.com/downloads/672f74b68064fe3f83d67cf1/ot83dil2pp" width="308" height="289"/>

A student is sitting on the right hand side in a bus, facing the direction of travel. The bus turns left while the student remains in the same position on the seat. While turning, the student experiences:

A) A force to the left and a force to the right

B) A resultant force backward&nbsp;

C) A resultant force to the right

D) A resultant force to the left

E) Zero resultant force

A 10-kg block slides down an inclined plane making an angle of 30° with the horizontal at a constant speed. The coefficient of kinetic friction between the block and the surface is
<img src="https://gateway.medhemmeh.com/downloads/672f74b68064fe3f83d67cf1/9rwt8p5nwi" width="393" height="243"/>

The figure shows two objects connected by a massless string. A force (F) of 30.0 N acts on the object with mass m1 = 5 kg to the right. If the coefficient of kinetic friction between all surfaces is 0.2, and the system accelerates at 2 m/s2, what is the tension in the string?
<img src="https://gateway.medhemmeh.com/downloads/672f74b68064fe3f83d67cf1/aazjy4c337" width="412" height="154"/>

E) The problem cannot be solved since m2 is not known

A box with a weight of 50 N rests on a horizontal surface. A person pulls horizontally on the box with a force of FM = 15 N and it does not move. To start it moving, a second person pulls vertically upward on the box with a force FV. If the coefficient of static friction is 0.4, what is the smallest vertical force FV, for which the box moves?
<img src="https://gateway.medhemmeh.com/downloads/672f74b68064fe3f83d67cf1/ef5qo5vtbg" width="231" height="120"/>

Two blocks are connected by massless string which runs over massless pulley. The coefficient of kinetic friction between m1 and the horizontal surface is Mk=0.4 And m1= 3.0 kg and m2=9.0 kg.
<img src="https://gateway.medhemmeh.com/downloads/672f74b68064fe3f83d67cf1/brqfpp3cjc"/>
The acceleration of the system in m/s^2:

Two blocks, A and B are at rest on a table as shown in the figure. The mass of block A is 1 kg. The magnitude of the normal force from the ground on block B is 39.2 N.
What is the mass (in kg) of block B?
<img src="https://gateway.medhemmeh.com/downloads/672f74b68064fe3f83d67cf1/kevtrwiywn"/>

Two blocks of masses 2 kg and 3 kg move on a horizontal frictionless surface and are subject to two horizontal forces of magnitudes 25N and 5 N.
What is the magnitude of the force (in N) exerted by block 2 on block 1: 
<img src="https://gateway.medhemmeh.com/downloads/672f74b68064fe3f83d67cf1/xoyimtz3fm" width="907" height="323"/>

The figure shows an object of mass m1= 2 kg placed on top of another object m2 = 3 kg which can move on a horizontal surface. A force (F) of 20.0 N acts on m2 to the right. If the coefficients of kinetic friction between the surfaces are 0.3, and the coefficient of static friction between m, and m2 is 0.5,
what is the force acting on m1?
<img src="https://gateway.medhemmeh.com/downloads/672f74b68064fe3f83d67cf1/xug5c6ke5u"/>

A 5.0-kg block rests on a 30.0° incline as shown in the figure. The coefficients of static friction and kinetic friction between the block and the incline are µS= 0.70 and µK= 0.50 respectively.
Find the minimum value of the force F that must act on the block just to start it moving up the incline is approximately:
<img src="https://gateway.medhemmeh.com/downloads/672f74b68064fe3f83d67cf1/bai908aqub"/>