A ball is launched vertically upward from a platform above the ground with speed

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

Problem

A ball is launched vertically upward from a platform

40\,\text{m}

above the ground with speed

20\,\text{m/s}

. Take the launch point as origin and upward as positive. Neglect air resistance. Which pair correctly gives the displacement

s

(with sign) when the ball hits the ground and the total distance travelled

D

? (a)

s=-40\,\text{m},\;D\approx60.8\,\text{m}

(b)

s=+40\,\text{m},\;D\approx80.8\,\text{m}

(c)

s=-40\,\text{m},\;D\approx80.8\,\text{m}

(d)

s=-40\,\text{m},\;D\approx40\,\text{m}