Reference no: EM132490496

Very large forces are produced in joints when a person jumps from some height to the ground.

a) Calculate the force exerted if a 84 kg person jumps from a 0.9 m high ledge and lands stiffly, compressing joint material 3.2 cm as a result. (Be certain to include the weight of the person.)(In N)

b) In practice the knees bend almost involuntarily to help extend the distance over which you stop. Calculate the force exerted if the stopping distance is 0.2 m. (In N)

c) Determine the ratio of the force exerted with stiff legs to the weight of the person.

d) Determine the ratio of the force with bent legs to the weight of the person.

A stone thrown off a bridge 40 m above a river has an initial velocity 8.5 m/s at an angle of 32 degrees above the horizontal.

(a) How much time does it take for the stone to reach the water? (In s)

(b) If the beginning point is where the stone is thrown, and the ending point is where the stone hits the water, find the x-component of the displacement of the stone. (In m)

(c) If the beginning point is where the stone is thrown, and the ending point is where the stone hits the water, find the y-component of the displacement of the stone. (In m)

A swimmer swims north at 0.12 m/s relative to still water across a river that flows at a rate of 0.205 m/s from west to east.

(a) What is the magnitude of the swimmer's velocity relative to the riverbank? (In m/s)

(b) What is the angle east of north of the swimmer's velocity? (In degrees)

A ball is thrown with speed 4.9 m/s at an angle 53 degree above the horizontal from the top of a cliff. The ball strikes the ground 21 m from the bottom of the cliff. Use g=9.80 m/s^2

(a) How long does it take the ball to strike the ground?(In s)

(b) How high is the cliff? (In m)