Question

Alice and bob are doing a space race from earth to the moon which is d 384000 km far away. Alices spaceship flies with a constant speed of v = 500 km h . Bobs spaceship starts slowly but accelerates constantly with a = 1.4 km h2 .

Answer 1

Explanation:

Alice flies at a constant speed therefore we can easily get the time she takes to cover the 384000 km from the earth to the moon.

V = 500 km/h

Time = Distance / speed

Time = 384000/500 = 768 hours

Alice takes 768 hours to travel to the moon.

As for Bob since he is moving under acceleration we need to use a kinematics equation for the motion.

a = 14 km/h²

S = 384000 km

u = 0

We will use the following kinematics equation as follows :

S = ut + 1/2at²

384000 = 0 + 0.5 × 14 × t²

384000 = 7t²

t² = 384000/7

t² = 54857.74

t = 234.22 hours

Bob takes 234.22 hours to reach the moon.