Forces in Equilibrium - Practice Problems
For
each problem: 1.
Draw a freebody
diagram. 2.
Draw in the x-
and y- axes. 3.
Resolve each
vector not already on the x- or y-axis into its x- and y- components. 4.
Write an
equation for the sum of forces in the x- and y-direction. If the system is at
rest or constant velocity, the net force is zero. 5.
Put your givens
into the equations and solve for the unknowns. |
¯
A 10.0 kg mass hangs
from two strings, each making an angle of 35.0¡ with the ceiling. What is the tension in each string? Solution
¯
A 15.0 kg block is at
rest on a 40.0¡ incline. Find the
magnitude of the normal force and the friction. Solution
¯
A 25.0 kg wagon and
rider is being pulled at constant velocity with a force of 50.0 N directed
along the handle. The handle makes
an angle of 65.0¡ with the horizontal.
Find the magnitude of the normal force and the force of friction. Solution
¯
A 20.0 kg lawn mower is
being pushed at constant velocity with a force of 65.0 N directed along the
handle. The handle makes an angle
of 60.0¡ with the horizontal. Find
the magnitude of the normal force and the force of friction. Solution
¯
Honors problem: Find the tensions in strings 1 and 2 supporting a
20.0 N rock hanging from the ceiling. Strings 1 and 2 make angles of 30.0¡ and
40.0¡ with the ceiling, respectively. Solution