Physics Questions & Answers

Physics Questions & Answers CHAPTER 4 1) A man is stranded on a raft (mass of man + raft = 1300 kg). By paddling he causes an average force P of 17 N in east direction. The wind also exert a force A on the raft whose magnitude is 15 N and points 67 degrees north of east. Ignoring any resistance from the water, find x and y component of the rafts acceleration. - CORRECT ANSWER- 1) (Ans. acc. x = 0.018, acc. y = 0.011). CHAPTER 4 10) A net force of 25N is applied for 5.7 s to 12-kg box initially at rest. What is the speed of the box at the end of the 5.7 s interval? - CORRECT ANSWER- (Ans. v = 11.87) CHAPTER 4 11) Two forces act on a 4.5-kg block resting on a frictionless surface as shown. What is the magnitude of the horizontal acceleration of the block? - CORRECT ANSWER- (ans. acc. = 1.78) CHAPTER 4 13) A 8-kg block is set moving with an initial speed of 6 m/s on a rough horizontal surface. If the force of friction is 12N, approximately how far does the block travel before it stops? - CORRECT ANSWER- (Ans. x = 12m) CHAPTER 4 14) A 250 N force is directed horizontally as shown to push a 29-kg box up an inclined plane at 27 degrees at a constant speed. Determine the magnitude of the normal force, Fn, and the coefficient of kinetic friction, uk. - CORRECT ANSWER- Fn = 367, uk = 0.26) CHAPTER 4 15) A system of two cables supports a 150 N ball as shown. What is the tension in the right-hand cable? 15) A system of two cables supports a 150 N ball as shown. What is the tension in the right-hand cable? - CORRECT ANSWER- (Ans. T2 = 300N) CHAPTER 4 16) A 10-kg block is connected to a 40-kg block as shown in the figure. The surface on that the blocks slide is frictionless. A force of 50 N pulls the blocks to the right. What is the magnitude of the tension T in the rope that connects the two blocks? - CORRECT ANSWER- (Ans. T = 10 N) CHAPTER 4 17) A block is pushed up a frictionless 30 degree incline by an applied force as shown. If F=25 and m = 3.0 kg, what is the magnitude of the resulting acceleration of the block? - CORRECT ANSWER- (Ans. a = 2.3 m/s2)