Question

To practice Problem-Solving Strategy 11.1 for conservation of momentum problems. An 80-kg quarterback jumps straight up in the air right before throwing a 0.43-kg football horizontally at 15 m/s. How fast will he be moving backward just after releasing the ball? How fast, (u_fx)_Q, will the quarterback be moving backward just after releasing the ball? Express your answer in meters per second to two significant figures. (u_fx)_Q = 8.1 times 10^-2 m/s Suppose that the quarterback takes 0.30 s to return to the ground after throwing the ball. How far d will he move horizontally, assuming his speed is constant? Express your answer in meters to two significant figures.

Answer 1

here,

mass , m = 80 kg

a)

the speed of quaterback just after releasing the ball , v = 8.1 * 10^-2 m/s

b)

the time taken by quaterback in air , t = 0.3 s

so the distance travelled by quaterback at constant speed , d = v * t

d = 2.43 * 10^-2 m