Download Equilibrium Problems

607 AP Physics
Name: ________________________
U3H1
Forces:
Lund
Equilibrium (Fnet = 0)
1. An object acted on by three forces moves with constant velocity. One force
acting on the object is in the positive x direction and has a magnitude of 6.5 N; a
second force has a magnitude of 4.4 N and points in the negative y direction. Find
the magnitude of the third force acting on the object.
2. A 10-kg sign is suspended by three ropes, as shown in the figure below. What is
the tension on each of the ropes?
(T1=217N, T2=288N)
3. A 15 m long rope is strung horizontally on two (vertical) poles. When a 47 kg mass
is hung at the mid-point of the rope, it sags 11°(angle rope makes to the horizontal).
What is the tension in the rope? (T=1232N)
4. The rectangular hanging block has a mass of 5 kg. Find the unknown mass of the
spherical block and the tensions in the ropes. (T1=T2=50N; T3=83N; T4=67N)
5. A 32.53 N light hangs at equilibrium from two cables at angles 78.3 and 60.2 with
respect to the ceiling. What is the tension in the first cable? (T1=9.85N)
607 AP Physics
Name: ________________________
Lund
6. A lamp weighs 150 N and is supported equally by two wires that form an angle of
120 degrees with each other.
a. What is the tension in each of these wires? (T=150N)
b. If the angle between the wires is reduced to 90 degrees, what is the new tension
in each wire? As the angle between the wires increases, what happens to the force
in the wires? (goes up)
7. Two identical uniform smooth spheres, each of weight W, rest as shown below at
the bottom of a fixed, rectangular container. Find, in terms of W, the forces
acting on the spheres by (a) the container surfaces and (b) by one another, if the
line of centers of the spheres makes an angle of 45o with the horizontal.
8. An Accident victim with a broken leg is being placed in traction. The patient
wears a special boot with a massless, frictionless pulley attached to the sole. The
foot and boot together have a mass of 4 kg, and the Doctor has decided to hang a
6.0 kg mass from the rope. The boot is held suspended by the ropes and does not
touch the bed.
(a) Determine the amount of tension in the rope by using Newton’s second law. If
the pulleys are frictionless the tension in the rope is constant throughout. (58.8 N)
(b) The net traction force needs to pull straight out on the leg. What is the proper
angle for the upper rope?
(67.8)
(c) What is the net traction force pulling on the leg?
(79.0 N)