Question

the ball is projected up from ground with speed 30 m /sec. what is the average velocity for time 0 to 4sec?

Answer 1

$average \: velocity = \frac{final \: velocity - initial \: velocity}{total \: time} \\ v : - final \: velocity(velocity \: at \: {4}^{th} second) \\ \\ v = u + at \\ v = 30 - 10 \times 4 \\ v = - 10m {s}^{ - } \\ \\ average \: velocity = \frac{ - 10 - 30}{4} \\ \frac{ - 40}{4} \\ - 10$
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