Question

How to calculate initial velocity of a projectile motion?

Answer 1

You’re probably going to have to deal with these equation in some form or another:

v ⃗ (t)=v ⃗ (0)+∫ t 0 a ⃗ (t)dt v→(t)=v→(0)+∫0ta→(t)dt

x ⃗ (t)=x ⃗ (0)+v ⃗ (0)t+∫ t 0 ∫ t 0 a ⃗ (t)dtdt x→(t)=x→(0)+v→(0)t+∫0t∫0ta→(t)dtdt

where

a ⃗ (t) a→(t) is acceleration at time t

v ⃗ (t) v→(t) is velocity at time t

v ⃗ (0) v→(0)is initial velocity

x ⃗ (t) x→(t) is position at time t.

x ⃗ (0) x→(0) is initial position

Since physics exercises often involve linear motion with constant acceleration, you can use:

v(t)=v(0)+at v(t)=v(0)+at

x(t)=x(0)+v(0)t+12 at 2  x(t)=x(0)+v(0)t+12at2