Problema Solution
A toy rocket is launched at an initial velocity of 14.7 m/s from a 49-m-tall platform. The height h of the object at any time t seconds after launch is given by the equation
h=−4.9t 2 +14.7t4+9
When will the rocket hit the ground?
Answer provided by our tutors
initial v=14.7 height of platform =49
this eq is written with respect to platform
for hitting ground h=-49 m
put h=-49 in the eq and solve for t
-49=-4.9 t^2 +14.7t
solve for t =5 sec
another value of t=-2 but it is rejected as t can not be negative