Question

The graph gives the vertical velocity of the rocket versus time after it is launched at t = 0.0 s. The rocket starts climbing with a constant speed of 23 m/s. At t = 2.0 s the rocket engine shuts off and the rocket is then in free-fall motion and falls back to the ground. What maximum height above the ground does the rocket reach?

Answer 1

Distance traveled with constant velocity in the first two seconds

= (23 m/s) x (2 s ) = 46 m

After the engine is shut off at highest point velocity becomes zero and in this duration acceleration due to gravity is -9.8 m/s²

^{Distance traveled,}

  

= 27 m

Therefore maximum height above the ground reached by the rocket

= 46 +27 = 73 m