Posted by Chan on .
A ball is thrown vertically upward with a speed of +12.0m/s.
A. how long the ball take to hit the ground after it reaches it highest point?
B. What is its velocity when it returns to the level from with it started?

Physic 
Chan,
A tortoise can run with a speed of 0.12m/s and a hare can run 20 times as fast. In a race, they both start at the same time, but the hare stops to rest for 2.0 minutes. The tortoise wins by a shell(25cm).
A. how long does the race takes?
B. What is the length of race? 
Physic 
drwls,
Please post one question at a time.
The speed when the ball hits the ground will again be 12 m/s (because of conservation of energy), but the direction will be reversed, making it 12.0 m/s.
The time of flight AFTER reaching max height will be the time it takes to accelerate to a speed of 12 m/s, which is 12/g = 12/9.8 s. 
Physic 
Taylor,
A tortoise can run with a speed of 13.0 cm/s, and a hare can run 20 times as fast. In a race, they both start at the same time, but the hare stops to rest for 5.0 minutes. The tortoise wins by a shell (40 cm).
(a) How long does the race take?
s
(b) What is the length of the race?
m