WorksheetsFriction
Total questions: 30
Worksheet time: 31mins
Static Friction is present only when an object is at rest.
True.
False.
A block is pulled along a rough level surface at constant speed by the force . The figure shows the free-body diagram for the block. FN represents the normal force on the block; and f represents the force of kinetic friction. What is the magnitude of FN?
P
f
2mg
mg
A 27.6 kg block is pulled along a rough level surface at constant velocity by the force . The figure shows the free-body diagram for the block. FN represents the normal force on the block; and f represents the force of kinetic friction. The coefficient of kinetic friction is 0.30, what is the strength of P?
4.0 N
81 N
270 N
27.6 N
A 2.0-N force acts horizontally on a 10-N block that is initially at rest on a horizontal surface. The coefficient of static friction between the block and the surface is 0.50.What is the magnitude of the frictional force that acts on the block?
5 N
8 N
2 N
0 N
A 2.0-N rock slides on a frictionless inclined plane. Which one of the following statements is true concerning the normal force that the plane exerts on the rock?
The normal force is 2.0 N
The normal force is greater than 2.0 N
The normal force is less than 2 N, but greater than 0 N
The normal force is 0 N.
Under what condition(s) will an object be in equilibrium? (Hint: An object can be in static equilibrium or dynamic equilibrium).
Only if the object is at rest can it be in equilibrium.
If the object is either moving with constant velocity or with constant acceleration, it is in equilibrium.
Only if the object is moving with constant acceleration can it be in equilibrium.
If the object is either at rest or moving with constant velocity, it is in equilibrium.
A block of mass M is held motionless on a frictionless inclined plane by means of a string attached to a vertical wall as shown in the drawing. What is the magnitude of the tension in the string?
Mg
Mgcos θ
Mg tan 𝜃
Mg sin 𝜃
A 2.50 kg block is held motionless on a rough inclined plane by means of a string attached to a vertical wall as shown in the drawing. θ=15o and the string is pulling with 10.0 N. What amount of static friction is present?
6.34 N
10.0 N
3.70 N
0 N
A 10-kg block is pushed against a vertical wall by a horizontal force of 100 N as shown in the figure. The coefficient of static friction, 𝜇s, between the block and the wall is 0.60; and the coefficient of kinetic friction, 𝜇k, is 0.40. Which one of the following statements is true, if the block is initially at rest?
The block will slide down the wall because the force of static friction can be no larger than 60 N.
The block will slide down the wall because the coefficient of kinetic friction is less than the coefficient of static friction.
The block will remain at rest because the coefficient of static friction is greater than the coefficient of kinetic friction.
The total force exerted on the block by the wall is directed horizontally.
Static and kinetic friction can be present simultaneously.
True
False.
To set an object in motion kinetic friction must be overcome.
True.
False.
What standard units do we use to communicate a frictional force?
kg
N
m
It is unitless.
What standard units do we use to communicate a coefficient of friction?
kg
N
m
It is unitless.
What is the force of gravity?
9.8 m/s2
The weight of an object. Fg=m*g
It is the mass of an object. In kilograms.
A 20.0 kg penguin slides at a constant velocity of 3.3 m/s down an icy incline. The incline slopes above the horizontal at an angle of 6.0°. Determine the coefficient of kinetic friction.
0.6
0
0.11
0.94
What is matter?
anything that has mass and takes up space
anything that can be felt
anything that can behave in many different ways
anything that exist on Earth
Which object is in motion?
A video of a car moving
A ball rolling down the hill
Bowling pins in a pyramid
A potato on the table
the combination (total) of all forces acting on an object
net force
speed
unbalanced force
balanced force
Resistance is
works against or slows motion.
Composes any physical substance
The total for acting on an object
Force that acts between any two masses
Which of the following is not a type of friction force?
Static Friction
Kinetic Friction
Rolling Friction
Rough Friction
Maximum value of Static Friction is called
Kinetic Friction
Sliding Friction
Limiting Friction
Rolling Friction
Which of the following are the characteristics of static friction force?
It can adjust its direction
It can adjust its magnitude
It has a limiting value
It cannot be zero
The component of contact force which acts tangential to the surface of contact is called
Normal Force
Friction Force
Tension Force
Spring Force
