Download Examples Torque and Center of Mass

Examples Torque and Center of Mass (gravity)
1. Rank in order, from least to greatest, the four torques. The forces all have the same magnitude and are pivoted at the
hinge.
2. The uniform bar shown has a length of 0.80 m. What is the net torque acting on the
bar? The bar has negligible mass.
3. A boy and his cat sit on a seesaw. The cat has a mass of 4 kg and sits 2 m from the center of
rotation. If the boy has a mass of 50 kg, where should he sit so that the see-saw will balance?
4. A jet transport has a weight of 1 X 106 N and is at rest on the runway. The two rear
wheels are 14.8 m behind the front wheel, and the plane’s center of gravity is 10.2 m
behind the front wheel. Determine the force normal exerted by the ground on the front
wheel. Determine the force normal exerted by the ground on each of the rear wheels.
5. A restaurant sign is attached to a wall by a pole and cable. The sign has a weight of 200 N and the
uniform, 1 m long pole has a weight of 50 N. What is the tension in the cable and the horizontal and
vertical components of the force on the pole from the wall?
6. A ladder of length 7.60 m and weight 335 N lens against a smooth vertical wall. The term
“smooth” means that the wall can exert only a normal force directed perpendicular to the wall
and cannot exert a frictional force parallel to it. A firefighter, whose weight is 870 N, stands 6.10
m up along the ladder from the bottom. Assume the ladder’s weight acts at the ladder’s center,
and neglect the weight of the hose. What is the minimum value of the coefficient of static
friction between the ladder and the ground, so that the ladder (with the fireman on it) does not
slip? Θ = 46o
7. A canoe of mass M has a passenger of mass M. Where is the center of mass?
8. Find the Center of Mass. Each block has the same mass
9. Center of mass and equilibrium