Question

A particle has an acceleration of +6.24 m/s2 for 0.300 s. At the end of this time the particle's velocity is +9.81 m/s. What was the particle's initial velocity?

Answer 1

The formula we will be using is:

Final Velocity = Initial Velocity + Acceleration * Time
v = u + at
u = v - at = 9.81 - 6.24*0.3 = 7.938 m/s

Answer 2

Answer:

$v_0=7.938\frac{m}{s}$

Explanation:

This is uniformly accelerated motion, that is to say a motion with constant acceleration, we can use the kinematic equations, especifically the which one that relate the change in speed to acceleration and time:

$v_f-v_0=at$

So, Rewriting for initial speed:

$v_0=v_f-at\\v_0=9.81\frac{m}{s}-(6.24\frac{m}{s^2})0.3s\\v_0=9.81\frac{m}{s}-1.872\frac{m}{s}\\v_0=7.938\frac{m}{s}$