Download UNIT 5

UNIT 6.5WS 3
1.
Name___________________________ Per____
An elevator is moving up at a constant velocity of 2.5 m/s, as illustrated in
the diagram below: For this entire worksheet, the pig has a mass of 85. Kg.
A. Determine the net force on the pig. Draw a force diagram and net
force diagram.
B. Sketch a velocity vs. time graph for porky (assume upward is
positive).
V
(m/s)
t (s)
C. Write the net force equation for porky. Σ Fy = ________________________
D. What is Porky's weight?
E. According to your equation, what must the normal force (floor on pig) be? Show your work.
FN = ___________
2.
The elevator now accelerates upward at 2.0 m/s2.
A. Determine the net force on the pig and then construct a force diagram and a net force
diagram for the pig.
B. Sketch a velocity vs. time graph for porky (assume upward
is positive).
V
(m/s)
t (s)
C. Write the net force equation for porky. Σ Fy = ________________________
D. According to your equation, what must the normal force (floor on pig) be? Show your work
FN = __________
3.
Upon reaching the top of the building, the elevator accelerates downward at -3.0 m/s2.
A. Construct a force diagram for the pig. Also make a net force diagram.
B. Calculate all the forces on your diagram and add them to your diagram. Show your work for
each force.
4.
While descending in the elevator, the cable suddenly breaks.
A. Construct a force diagram and a net force diagram for the pig.
B. What force does the floor now exert on the pig?
FN = ___________
5.
A. Porky rides on a sled that is pulled with a constant tension force of 100 N across sticky snow.
The friction force is -9 N. Draw a force diagram and use Newton's 2nd law (ΣF = ma) to
calcuate Porky's acceleration.
85 kg
friction =
-9 N
B. Calculate μ, the coefficient of friction between the sled and the snow.
Ft = 100 N