Aball is released from a hot air balloon moving downward with a velocity of -10.0 meters/second and a height of 1,000 meters. how long did it take the ball to reach the surface of earth? given: g = -9.8 meters/second2. a. 11.2 seconds b. 12.1 seconds c. 13.3 seconds d. 13.5 seconds e. 14.2 seconds

Answer

E. 14.2 seconds

Explanation

We are going to use the Newton's law of  motion.

s = ut + (1/2)gt²

Where s ⇒ height

            g ⇒ acceleration due to gravity

              t ⇒ time taken to reach the surface of the earth.

              u ⇒ initial velocity

s = ut + (1/2)gt²

1,000 = -10t + (1/2)×-9.8×t²

10t + (1/2)×9.8×t² = -1000

4.9t² + 10t = -1000

t² + 2.0408t = 204.0816

t² + 2.0408t + 1.0204² = 204.0816 + 1.0204²

(t + 1.0204)² = 205.1228

t = +√205.1228 -1.0204                   or t = -√205.1228 -1.0204

 = 14.322 s                                                     =  - 15.342 s

Since time can not be negative, we take the answer to be: 14.322 seconds.

a sonic boom is a loud boom that breaks the sound barrier

explanation:

when jerome paddle in flowing river towards east the net speed of jerome will increase

so the net speed of jerome will be given as

now the speed of paul will be same as it is given as he is running on the ground

so

so here we can say since the speed of jerome is more so he will win the race

now as we know the distance so the time difference is given as

so jerome will reach first and the time difference will be 203.55 s or 3.4 min