This preview shows pages 1–3. Sign up to view the full content.
Practice Problems 8
1
. A 13.6 kg block is dragged over a rough, horizontal surface by a 73.2 N force acting at
16.6 degrees above the horizontal. The block is displaced 4.66 m, and the coefficient of
kinetic friction is 0.272. Find the work done by the 73.2 N force.
Answer:
3.27e+02 J
2
. Find the work done by the normal force.
Answer:
0 J
3
. What work does the gravitational force do on the block?
Answer:
0 J
4
. How much energy is lost due to friction?
Answer:
1.43e+02 J
5
. [1 point, 10 tries]
Find the total change in the block's kinetic energy.
Answer:
1.84e+02 J
6
. Calculate the scalar product of the vectors in the figure below.
Assume θ
1
= 109°, θ
2
= 130°,
F
= 37.2 N and
v
= 18.1 cm/s.
Answer:
5.77E+00 W
7
. A force
F
= (4.41
x
i
+ 2.85
y
j
) N acts on an object as it moves in the
x
direction from
the origin to
x
= 4.53 m. Calculate the work done on the object by the force.
Answer:
4.52E+01 J
This preview has intentionally blurred sections. Sign up to view the full version.
View Full Document8
. When a 4.43 kg mass is hung vertically on a certain light spring that obeys Hooke's
law, the spring stretches 2.91 cm. If the 4.43 kg mass is removed how far will the spring
This is the end of the preview. Sign up
to
access the rest of the document.
 Spring '08
 N. MCKAY
 mechanics, Force, Friction, Work

Click to edit the document details