Initial Velocity | MCQs

Explanation

Ball falls 20m, so time taken is found using:

s = 1/2 gt²

20 = 1/2 × 10 × t²

t = 2s

Vertical velocity when it hits the ground:

v_y = gt = 10 × 2 = 20 m/s

Since it hits at 45°, v_x = v_y = 20 m/s

Explanation

Step 1: Use projectile motion

The maximum range of a projectile (ignoring air resistance) is given by:

R=v^2sin(2θ)/g​

The maximum range occurs when θ=45∘the value is maximum at (i.e.,sin(90∘)=1).

Step 2: Plug in values

• $v = 12 text{m/s}$

• g=10 m/s^2

R=12^2⋅1 ​/ 10 

= 144/10

​=14.4 meters

Explanation

h = u²/2g = (16)² / (2 × 9.8) = 256 / 19.6 = 13.06 ≈ 13.1 m.