Question

When the space shuttle lands, it touches down on the runway with a speed of 125m/s. It is then slowed by a drag chute to a complete stop in 70.0 sec. Assuming the acceleration is constant, calculate the distance required for the shuttle to come to a complete stop.

Answer 1

here you know following
1.initial speed
2. time taken to stop
3. also that acceleration is constant.

so first step is calculate acccelaration using acc. = ( v(f) - v(i) ) / time
note here a will be negative.
then using that you calculate distance using formula
distance = v(i)*t + 0.5 a*t^2