Question

A ball is thrown vertically upwards at 1.2 ms decelerates uniformly at 10 ms2.How long will it take to reach zero velocity?
​

Answer 1

Answer:

u = 1.2m/s

v=0

a = -10m/s²

From the first equation of motion

We have,

v = u + at

0 = 1.2+-10*t

0 = -12t

t = 0/-12

Answer 2

Given :-

• Initial velocity (u) = 1.2 m/s
• Acceleration (g) = - 10m/s²
• Final velocity (v) = 0

To find :-

• Time to reach zero velocity

Solution :-

As we know that

→ v = u + gt

→ 0 = 1.2 + (-10) × t

→ 0 = 1.2 - 10t

→ 10t = 1.2

→ t = 1.2/10

→ t = 0.12 s

Hence,

• Time taken to reach zero velocity is 0.12s

Extra Information

• h = ut + ½ gt²
• v² = u² + 2gh
• S.I unit of time is second
• Minus shows retardation