Question 4. A rod is lying on the top of a table. One end of the rod is hinged to the table so that the rod can rotate freely on the table top. Two forces, both parallel to the table top, act on the rod at the same place. One force is directed perpendicular to the rod and has a magnitude of 31 N. The second force has a magnitude of 52 N and is directed at an angle with respect to the rod. If the sum of the torques due to the two forces is zero, what must be the angle? Ans: 36.59°

What is the student’s weight?

Bob and Anna sit on opposite ends of a uniform see-saw which is 12.0 m in length. The see-saw is balanced by a fulcrum which is located 4.00 m from Bob. Bob has a mass of 85.0 kg, and the see-saw itself has a mass of 100 kg. Anna’s mass is unknown. NOTE THAT THE FULCRUM IS NOT PLACED AT THE CENTER OF MASS OF THE SEE- SAW!!! a)   What is the net torque on the see-saw? Explain clearly and briefly how you know. b) Draw a properly labeled extended force diagram of the see-saw   c) Solve for Anna’s mass. Show your work clearly!

You're carrying a 3.4-m-long, 24 kg pole to a construction site when you decide to stop for a rest. You place one end of the pole on a fence post and hold the other end of the pole 35 cm from its tip. How much force must you exert to keep the pole motionless in a horizontal position?

A uniform 36.0-kg beam of length ℓ = 4.20 m is supported by a vertical rope located d = 1.20 m from its left end as in the figure below. The right end of the beam is supported by a vertical column. Answer parts a-b.

A 4.00 meter long uniform ladder with mass 10.0 kilograms leans against a wall, making an angle of 60 degrees with the floor. A person, who has a mass of 60 kilogams, stangs exactly halfway up the ladder. The wall is frictionless. The friction between the bottom of the ladder and the floor keeps the ladder from slipping. Find the magnitude and direction of the force that acts on the bottom of the ladder.

A beam is connected to the floor by a hinge. A rope is attached to the other end of the beam. The other end of the rope is connected to the ceiling. There is box sitting on the beam (see figure).The angle between the beam and the floor is 8.60 degrees. The angle between the rope and the horizontal is 20.0 degrees. The beam is 4.00-m long and has a mass of 6.80 kg. The box sits a distance of d = 0.620 m from the upper end of the beam and has a mass of 8.00 kg. The tension in the rope is 205.7 N.What is the horizontal component of the force on the beam due to the hinge?