Question

A ball is thrown vertically upward and rises to a height of 126.5 m
1) calculate the velocity by which the ball was thrown upward

2) the time taken by the ball to reach the highest point.

Answer 1

Explanation:

2) the time taken by the ball to reach the highest point

Answer 2

Let velocity of object is u

we know, at 126.5m height object will be rest .

so, final velocity = 0

A/C to kinematics equations,

v² = u² + 2aS

v² = u² +2(-g) × h

0 = u² - 2 × 9.8 x 126.5

u² = 2,479.4

u = √2,479.4  

  = 49.79 m/s

 =  50 m/s

Time taken by the object to reach the highest point is t

v = u + at

0 = 49.79 - 10t

t = 50/10 sec

t = 5 sec