Question

An object is projected upwards with a velocity of 100$m/s$. It will strike the ground after (approximately)

• A. 10 sec
• B. 20 sec
• C. 15 sec
• D. 5 sec

Answer 1

Answer: (B)

20 sec

Answer 2

Time of flight $= \frac{2u}{g} = \frac{2 \times 100}{10} = 20\mspace{6mu}\sec$