Question

The ball is projected up from ground with speed 30m/s . What is average velocity for time 0 to 4 sec

Answer 1

Answer:

$V_{average}=10.4\:m/s$

Step by step explanation:

It is given that:

• The initial velocity, $v_i=30\:m/s$
• Time, $t=4\:s$

The average velocity = $\frac{total\:distance}{total\:time}$

Therefore, we need to find the distance covered. From the rules of Kinematics:

$d=v_it+\frac{1}{2}at^2$

In this example, acceleration 'a' will be negative the gravitational force of acceleration 'g' ($-9.8\:m/s^2$); because the ball is moving upwards, opposite to the direction of the gravity.

Hence,

$d=30(4)+\frac{1}{2}(-9.8)(4)^2\\d=41.6\:m$

Therefore, the average velocity = $\frac{41.6}{4}=10.4\:m/s$