A hailstone traveling with a velocity of 43 meters/second comes to a virtual stop 0.28 seconds after hitting water. What is the magnitude of its acceleration in the water?

A) 12 meters/second2
B) 1.5 × 102 meters/second2
C) 78.6 meters/second2
D) 6.5 × 10-3 meters/second2

Question

A hailstone traveling with a velocity of 43 meters/second comes to a virtual stop 0.28 seconds after hitting water. What is the magnitude of its acceleration in the water?

A) 12 meters/second2
B) 1.5 × 102 meters/second2
C) 78.6 meters/second2
D) 6.5 × 10-3 meters/second2

anonymous · Answer

Use the equation of kinematics for uniformly accelerated motions
$$v=u+at$$
$$u=43ms^{-1}$$$$v=0ms^{-1}$$$$t=0.28s$$$$a=\frac{v-u}{t}$$
Your acceleration will be negative as the hailstone is deaccelerating
So it's magnitude you can take by$$|a|=\left| \frac{v-u}{t} \right|$$