- #1

meteoguy04

We were assigned a problem set for homework, a total of 7 problems. Below are the questions, and the work I used to get the answer. I'm just looking for a second set of eyes to point out any mistakes I may have made.

thanks!

=======

6.(a) How long will it take a freely falling body to acquire a speed of 58.8 m/s? (b) How far will it have fallen during that time?

a) t = v/a t = 58.8 / 9.8 = 6s

b) d=VoT + 1/2 gt^2

vo = 58.8 m/s

vf =

a = 9.8 m/s

t = 6 secs

d = 529.2 <=== Answer

10) A coin dropped from the top of a precipice takes 5.00 s to hit the ground. How high is the precipice?

d = 1/2 at^2

d = 1/2 * 9.8 * 5.00

= 24.5 m

11) A ball thrown vertically upward returns to the hand of the thrower 6.00 s later. (a). For how many seconds did the ball fall after reaching its high point? (b) How high did the ball go?

a) t = 2d/a

t = 2 * 176.4/9.8 = 36 = 6

b) d = 1/2 at^2

d = 1/2 * 9.8 * 6.0s^2

= 176.4 m

13) An object falls to the floor from a shelf 2.5 m high. With what speed does it strike the floor?

2.5 m * 9.8

= 24.5 m/s

16) (a) With what speed does a freely falling body dropped from a height of 88.2 m hit the ground? (b). How long does the body take to fall this distance?

a) v^2 = 2ad

v^2 = 2(9.8)(88.2)

= 1728.72

b) t = 2d/a t = 2(88.2)/9.8 = 18s

18) A bullet shot vertically upward has an initial speed of 588 m/s. (a). How long does it take before the bullet stops rising? (b). How high does the bullet go during this time?

a) t = v/a t = 588/9.8 = 60s

b) d = 1/2 at^2

d = 1/2 (9.8) (60)^2

= 1760 m

20) An object dropped from a ballon descending at 4.2 m/s lands on the ground 10 s later. What was the altitude of the balloon at the time the object was dropped?

vf = Vo + at

vf = 4.2 m/s + 9.8 * 10s

= 102.2 m