Inclined_Plane_Rev
TEACHER ANSWER KEY
November 22, 2004
'see explanation below'
1. Base your answer on the information and accompanying diagram.
A 10.0-kilogram block slides at constant speed down a plane inclined at 20.o to
the horizontal, as shown.
On the diagram, draw an arrow to represent and identify the direction of each
of the three forces (weight, friction, normal force) acting on the block. Begin
each arrow at point C and label each arrow with the force that it represents. [3]
'see explanation below'
2. Base your answer on the information and accompanying diagram.
A 10.0-kilogram block slides at constant speed down a plane inclined at 20.o to
the horizontal, as shown.
Determine the weight of the block. [Show all calculations, including the
equation and substitution with units.] [2]
'see explanation below'
3. Base your answer on the information and accompanying diagram.
A 10.0-kilogram block slides at constant speed down a plane inclined at 20.o to
the horizontal, as shown.
In one or more complete sentences, describe the change in the motion of the
block as the angle of inclination is increased to 30.o. [1]
'see explanation below'
4. Base your answer on the diagram and the information provided.
A 160.-newton box sits on a 10.-meter-long frictionless plane inclined at an
angle of 30.o to the horizontal as shown. Force (F) applied to a rope attached to
the box causes the box to move with a constant speed up the incline.
On the diagram, or on a separate piece of paper, construct a vector to represent
the weight of the box. Use a metric ruler and a scale of 1.0 centimeter = 40.
newtons. Begin the vector at point B and label its magnitude in newtons. [2]
'see explanation below'
5. A box of mass m is held motionless on a frictionless inclined plane by a rope
that is parallel to the surface of the plane. On the diagram provided, draw and
label all of the force vectors acting on the box. [3]
2
6. The accompanying diagram represents a block sliding down an incline.
Which vector best represents the frictional force acting on the block?
1. A
3. C
2. B
4. D
1
7. A book weighing 20. newtons slides at constant velocity down a ramp
inclined 30.o to the horizontal as shown in the diagram.
1. 10. N up the ramp
3. 10. N down the ramp
2. 17 N up the ramp
4. 17 N down the ramp
1
8. The diagram represents a 10.-newton block sliding down a 30.' incline at a
constant speed. The force of friction on the block is approximately
1. 5.0 N
3. 49 N
2. 10. N
4. 98 N
No Explanation Available.
2
9. In the diagram, the weight of a box on a plane inclined at 30', is represented
by the vector W. What is the magnitude of the component of the weight (W)
that acts parallel to the incline?
1. W
3. 0.87W
2. 0.05W
4. 1.5W
No Explanation Available.
4
10. A 1.0-kilogram block is placed on each of four frictionless planes inclined
at different angles. On which inclined plane will the acceleration of the block
be greatest?
4
11. The accompanying diagram shows a 50.-kilogram crate on a frictionless
plane at angle theta to the horizontal. The crate is pushed at constant speed up
the incline from point A to point B by force F.
If angle theta were increased, what would be the effect on the magnitude of
force F and the total work W done on the crate as it is moved from A to B?
1. W would remain the same and the
3. W would increase and the magnitude
magnitude of F would decrease.
of F would decrease.
2. W would remain the same and the
magnitude of F would increase.
4. W would increase and the magnitude
of F would increase.
4
12. Three forces act on a box on an inclined plane as shown in the
accompanying diagram. [Vectors are not drawn to scale.]
If the box is at rest, the net force acting on it is equal to
1. the weight
3. friction
2. the normal force
4. zero
3
13. In the diagram shown, a box is at rest on an inclined plane.
Which vector best represents the direction of the normal force acting on the
box?
1. A
3. C
2. B
4. D