A student throws a set of keys vertically upward to his fraternity brother, who is in a window 3.95 m above. the brother's outstretched hand catches the keys 1.75 s later. (take upward as the positive direction. indicate the direction with the sign of your answer.) (a) with what initial velocity were the keys thrown?

Question

Liberty Stark

Physics

22 April, 22:56

A student throws a set of keys vertically upward to his fraternity brother, who is in a window 3.95 m above. the brother's outstretched hand catches the keys 1.75 s later. (take upward as the positive direction. indicate the direction with the sign of your answer.) (a) with what initial velocity were the keys thrown?

+2

Answers (1)

Know the Answer?

Axel Sims · Answer 1

Answer: Vo = 10.84 m/s

Explanation:

1) dа ta:

d = 3.95m

t = 1.75s

g = 9.81 m/s²

Vo = ?

2) Formula

Vertical motion ⇒ d = Vo*t - g*t² / 2

3) Solution

Clearing Vo, you get:

Vo = [ d + gt² / 2] / t

⇒ Vo = [ 3.95m + 9.81 m/s² (1.75s) ² / 2 ] / 1.75s = [3.95m + 15.02m] / 1.75s

Vo = 18.97 m / 1.75s = 10.84 m/s