Numerical problem - a ball thrown vertically upwards -1 PhysicsTeacher

Last updated on June 13th, 2022 at 08:28 am

Here, we will Solve the following numerical problem based on the vertical motion of a ball – when a ball is thrown vertically upwards.

Question

When a ball is thrown vertically upwards, it goes through a distance of 19.6 m. Find the initial velocity of the ball and the time taken by it to rise to the highest point. (Acceleration due to gravity, g=9.8 ms^-2) [3 MARKS]

Solution:

Distance traversed =s=19.6 m

say, initial velocity = u

and, say the time taken to rise to the highest point = t

We know that the velocity at the highest v = 0

Using the following equation of motion with retardation, we can find the initial velocity = u

v²=u²– 2gs

=> 0 = u² – 2 x 9.8 x 19.6

=> u²=19.6 x 19.6

u = 19.6 m upwards

To find out the the time taken to rise to the highest point (t) we will use the following equation:

v = u – gt

=> 0 = u – gt

=> t = u/g = 19.6/9.8 s = 2 seconds