Arocket-launching vehicle is moving forward at a constant velocity of 5 m/s. a cannon on the vehicle shoots a shell straight up with a velocity of 20 m/s. the shell moves without friction, (no air resistance). how high does the shell go, in m?

For any object thrown upwards where only the force of gravity is acting upon it, uses the following formula for the maximum height attained.

H= v²/2g, where g = 9.81 m/s²

There are two information of velocities are given. However, we use the 20 m/s information because this is the launch velocity. Hence, the solution is as follows:

H = (20 m/s)²/2(9.81 m/s²)
H = 20.4 m

My answer is opptionc, just check with anyone else

As newton's first law states a object in motion stays in motion