How Long Does a Ball Take to Fall Back Down After Being Thrown Upward?

[manzoor]

Homework Statement

A boy throws a ball vertically upward from the ground with the velocity 25 m/s. On its way down it is caught 5 m above the ground. How long did the trip take and with what velocity was it coming down?

Homework Equations

The Attempt at a Solution

Which equation of motion should I use? Please give me hints

 

[rl.bhat]

Use
y = Vi*t - 1/2*g*t^2.
Solve the quadratic to find t. You will get two values. For return journey, take the larger value of t.

 

[manzoor]

What do you mean by solve the quadratic for t?

 

[rl.bhat]

What do you mean by solve the quadratic for t?

In the problem y is given. g is known. Initial velocity is given. Substitute these values in the kinematic equation and solve for t.