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1. An object is projected upward with a velocity of 125 m/s.
(a) To what height will it rise?
(b) How long will it take to reach that height?
(c) What will be the total time elapsed until it strikes the earth?

Respuesta :

Answer:

A) s = 796.38 m

B) t = 12.742 s

C) T = 25.484 s

Explanation:

A) First of all let's find the time it takes to get to maximum height using Newton's first equation of motion.

v = u + gt

u = 125 m/s

v = 0 m/s

g = 9.81 m/s²

Thus;

0 = 125 - 9.81(t)

g is negative because motion is against gravity. Thus;

9.81t = 125

t = 125/9.81

t = 12.742 s

Max height will be gotten from Newton's 2nd equation of motion;

s = ut + ½gt²

s = (125 × 12.742) + (½ × -9.81 × 12.742²)

s = 1592.75 - 796.37

s = 796.38 m

B) time to reach maximum height is;

t = u/g

t = 125/9.81

t = 12.742 s

C) Total time elapsed is;

T = 2u/g

T = 2 × 125/9.81

T = 25.484 s

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