UNIVERSITI TUNKU ABDUL RAHMAN
: Centre for Foundation Studies (CFS)
: Foundation in Science
: Year 1 / Trimester 1
Tutorial 4: Application of Newton's Laws.The distance between two telephone poles is 50.0 m. When a 1.00 kg bird lands on the telephone wire midway between the poles, the wire sags 0.200 m. Draw a free-body diagram of the bird. How much tension does the bird produce in the wire? Ignore the weight of the wire. [614 N]A 40 kg crate rests on a horizontal floor, and a 75 kg person is standing on the crate. Determine the magnitude of the normal force that (a) the floor exerts on the crate and (b) the crate exerts on the person. [(a) 1.13 x 103 N, (b) 735 N]A worker stands still on a roof sloped at an angle of 45° above the horizontal. He is prevented from slipping by a static frictional force of 450 N. Find the mass of the worker. [85 kg]A 4.0-kg bucket of water is raised from a well by a rope. If the upward acceleration of the bucket is 5.0 m/s2, find the force exerted by the rope on the bucket. [59 N]A block is pressed against a vertical wall by a force, as the drawing shows. This force can either push the block upward at a constant velocity or allow it to slide downward at a constant velocity. The magnitude of the force is different in the two cases, while the directional angle ( is the same. Kinetic friction exists between the block and the wall, and the coefficient of kinetic friction is 0.250. The weight of the block is 39.0 N, and the directional angle for the force is ( = 30.0°. Determine the magnitude of when the block slides (a) up the wall and (b) down the wall. [(a) 52.6 N, (b) 39.4 N]A 3.0 kg block is at rest on a horizontal floor. If you push horizontally on the 3.0 kg block with a force of 12.0 N, it just starts to move. (a) What is the coefficient of static friction? (b) A 7.0 kg block is stacked on top of the 3.0 kg block. What is the magnitude F of the force, acting horizontally on the 3.0 kg block that is required to make the two blocks start to move? [(a) 0.41, (b) 40 N]The systems shown in figure below are in equilibrium. If the spring scales are calibrated in newtons, what do they read? Ignore the masses of the pulleys...