Stone P is projected horizontally with a speed of from the top of a cliff high

PHYSICS · Single correct · A Level · Physics · Mechanics and materials · Mechanics and materials

Problem

Stone P is projected horizontally with a speed of

12\,\text{m s}^{-1}

from the top of a cliff

20\,\text{m}

high. At the same instant, stone Q is projected horizontally with a speed of

24\,\text{m s}^{-1}

from another cliff so that both stones take equal times to reach the ground. What is the height of the second cliff? (Take

g = 10\,\text{m s}^{-2}

.) (a)

40\,\text{m}

(b)

20\,\text{m}

(c)

10\,\text{m}

(d)

34\,\text{m}