Question

A particle is thrown upwards with a velocity of 20m/s. Find its velocity after 1 sec and also after 3 sec

Answer 1

After one second the velocity would be 20m/s and after 3 second it would be 6.6666667m/s

Answer 2

Answer:

A particle is thrown upwards with a velocity of 20m/s. Its velocity after

1s will be $10.2m/s$ and velocity after 3s will be $-9.4m/s$

Explanation:

• We can solve this problem using the first equation of motion.

        It is given by,

        $V = u+at$    ...(1)

       Where $V$is the final velocity of the body, $u$ is the initial velocity, $a$ is the acceleration due to gravity, and $t$is the time taken by the body

       since the body is thrown upwards,

        $a = -g$

        We know g is the acceleration due to gravity

        $g= 9.8m/s^2$

• From the question,

       Case 1:

       The initial speed of the body = $20m/s$

       The time is taken = $1s$

       Substitute these values into equation (1)

        $V = 20-(9.8\times 1)$

             $= 10.2m/s$  

      Case 2:

       The initial speed of the body = $20m/s$

       The time is taken = $3s$

       Substitute these values into equation (1)

        $V = 20-(9.8\times 3)$

             $= -9.4m/s$