Download Force Test 14

1.
For a block on a slope, as shown, which combination of mass and coefficient of static
friction u will result in the maximum angle Θ without slipping?
a. 1Kg,
u
b. 2Kg,
.9u
c. 4Kg,
.8u
d. 6Kg,
.7u
e. 8Kg,
.6u
2.
The two boxes are pulled forward at a constant acceleration, with a
tension T, at 30 degrees above the horizontal. The first box has a mass
2M and the second has a mass M, no friction exists. What is the normal
force magnitude that M exerts on 2M?
a. (T/3)
b. (2T/3)
c. (T/3) *cos 30
d. (2T/3)*sin 30
e. (2T/3) *cos 30
3.
Two stars of identical mass, separated by a distance D, revolve around
each other. What must be the speed of each star?
a.
.25𝐺𝑀
√
b.
√
c.
√
d.
e.
𝐷
.5GM
D
GM
D
2𝐺𝑀
√
𝐷
4𝐺𝑀
√
𝐷
4.
A single force is applied in the horizontal direction to a 2Kg block on a frictionless surface. The force applied results in
a velocity according to the function V=2t2. If the string will break when 24N of force or more is applied, how long will
it take before the string breaks?
a. 1s
b. 2s
c. 3s
d. 4s
e. 5s
5.
.The speed of an object on a circular path changes according to the graph shown. What is
the best graph for the centripetal acceleration as a function of time?
6.
A 100Kg pilot is executing a vertical circular loop of radius 1000m in her plane above the earth at a constant speed of
200m/s. Assuming the acceleration due to earth’s gravity is constant, the force by the seat on the pilot at the lowest
point of the loop would be__________
a. 100N
b. 1500N
c. 3000N
d. 4000N
e. 5000N
7.
The two snowcats are pulling the housing unit at a steady rate (toward the
top of the page). The angles are shown as 48 on the left and 32 on the
right. How can we compare Force FA and FB? The sum of the two vectors
FA and FB will be____________ the magnitude of friction.
a. FA>FB,
Less than
b. FA=FB
Greater than
c. FA<FB,
Equal to
d. FA<FB,
Less than
e. FA<FB,
Greater than
8.
A ball bounces off the pavement, on the path shown. The force of the
impact that the pavement applies to the ball will be directed________.
a. Up
b. Up and to the right
c. Up and to the left
d. Down
e. Down and to the
The following applies to the next two questions.
A block slides down a frictionless ramp onto a
frictionless tabletop. At the
bottom of the ramp, the block has a speed v. The wall is rough with a coefficient of friction u.
9.
What is the tangential (linear) acceleration as the block starts to slides
around the ramp at point P? (assume the path is circular at this moment)
a. ug
b. uvg
c. umg
d. (uv2)/R
e. (uv)/R2
10. At point Q, identify the vector that best represents direction of the net
force applied to the block. (assume the block is still moving at Q)
a. a
b. b
c. c
d. d
e. e
1.
Santa’s Sleigh makes a banked turn through the air at velocity V. The bank through the air
is made in a perfectly circular path of radius R, where altitude does not change during
motion. During this bank the sleight is oriented perfectly at angle Θ above the horizontal,
so that no friction is required to keep the packages, represented by package M, in place.
a. Draw a free body diagram on the block M provided
b. How can we compare the magnitude of the forces shown in your free body
diagram? Justify your answer
c. Calculate the bank angle Θ in terms of the other variables given and
fundamental constants.
The package (M) then falls out of the sleigh after one of the reindeer moves unexpectedly. The
mass M is 20Kg and moves through the air in the presence of drag. Also |Fd|=kv and terminal
velocity is 60m/s for the package
d.
e.
f.
Calculate the constant, k.
Starting with newton’s second law, create a differential equation that
would allow for the determination of the velocity of the object as a
function of time.
Arrange the previous equation for integration, substituting limits but do
not integrate.
2.
The system starts at rest with the box initially at .5meters above the ground. At time zero, the forklift driver is
accelerating forward at 3m/s2, while the lift also has an accelerating upward at .5m/s2. The 300Kg package does not
shift on the lift. Assume acceleration due to gravity is 10m/s2.
a. Draw a free body diagram showing all forces acting on the package.
b.
c.
d.
e.
What is the normal force exerted by the lift on the package?
Calculate the coefficient of friction between the lift and the package.
Determine an equation for the path of the box that expresses y as a function of x (and not of t), assuming
that, at time t = 0, the box has a horizontal position x = 0.
Graph the position equation below