Question1
A uniform bar of length 46 m and mass 3 kg is attached to a wall with a hinge that exerts a horizontal force Hx and a vertical force Hy on the bar. The bar is held by a cord that makes a 90 angle with respect to the bar and 44 with respect to the wall. What is the magnitude of the horizontal force Hx on the pivot? The acceleration of gravity is 9.8 m/s2.
Answer in units of N
Question2
A 39.0-kg child swings in a swing supported by two chains, each 2.98m long. The tension in each chain at the lowest point is 440 N.
(a) Find out the child's speed at the lowest point.
(b) Find out the force exerted by the seat on the child at the lowest point.
Question3
A spring with a force constant of 135 N/m is used to push a 0.27-kg block of wood against a wall. Find out the least compression of the spring needed to keep the block from falling, given that the coefficient of static friction between block and wall is 0.39.