Question 4 A 50-kg crate slides down a ramp as shown below. Assuming that the ramp is frictionless, find the acceleration of the crate. 60° 50 kg

A child of mass m swings in a swing supported by two chains, each of length R. If the tension in each chain at the lowest point is T, find (a) the childs speed at the lowest point and (b) the force exerted by the seat on the child at the lowest point. (Ignore the mass of the seat.)

Professional Application During a visit to the International Space Station, an astronaut was positioned motionless in the center of the station, out of reach of any solid object on which he could exert a force. Suggest a method by which he could move himself away from this position, and explain the physics involved.

While sliding a couch across a floor, Andrea and Jennifer exert forces FA and FJ on the couch. Andrea’s force is due north with a magnitude of 130.0 N and Jennifer’s force is 32 east of north with a magnitude of 180.0 N. (a) Find the net force in component form. (b) Find the magnitude and direction of the net force. (c) If Andrea and Jennifer’s housemates, David and Stephanie, disagree with the move and want to prevent its relocation, with what combined forceFDS should they push so that the couch does not move?

A race car is moving around a circular track at a constant speed of 65 m/s. It continues moving in this manner at this speed for 15 minutes. During this time, what is the direction of the net force exerted on the race car?

A basketball player jumps straight up for a ball. To do this, he lowers his body 0.300 m and then accelerates through this distance by forcefully straightening his legs. This player leaves the floor with a vertical velocity sufficient to carry him 0.900 m above the floor. (a) Calculate his velocity when he leaves the floor. (b) Calculate his acceleration while he is straightening his legs. He goes from zero to the velocity found in (a) in a distance of 0.300 m. (c) Calculate the force he exerts on the floor to do this, given that his mass is 110.0 kg.

An object executes circular motion with constant speed whenever a net force of constant magnitude acts perpendicular to the velocity. What happens to the speed if the force is not perpendicular to the velocity?

Two objects are connected by a siring that passes over a frictionless pulley as in Figure 5.14a. where m1 m2 and a1 and a2 are the magnitudes of the respective accelerations. Which mathematical statement is true regarding (he magnitude of the acceleration a2 of the mass m2? (a) a2 g (b) a2 g (c) a2 = g (d) a2 a1 (e) a2 a1 Figure 5.14 (Example 5.9) The Atwood machine, (a) Two objects connected by a massless inextensible string over a frictionless pulley. (b) The free-body diagrams for the two objects.

Give reasons for the answers to each of the following questions: (a) Clan a normal force be horizontal? (b) Can a normal force be directed vertically downward? (c) Consider a tennis ball in contact with a stationary floor and with nothing else. Can the normal force be different in magnitude from the gravitational force exerted on the ball? (d) Can the force exerted by the floor on the hall be different in magnitude from the force the ball exerts on the floor?

A baseball catcher is performing a stunt for a television commercial. He will catch a baseball (mass 145 g) dropped from a height of 60.0 m above his glove. His glove stops the ball in 0.0100 s. What is the force exerted by his glove on the ball?