Question

An elevator in which a man is standing is moving upwards with a speed of 10m/s. If the man drops a coin from a height of 2.45 meter, it reaches the floor of the elevator after a time :

(g = 9.8 m/s²)

• A. $\sqrt{2}$s
• B. $\frac{1}{\sqrt{2}}$s
• C. 2s
• D. $\frac{1}{2}$s

Answer 1

Answer: (B)

$\frac{1}{\sqrt{2}}$s

Answer 2

Since elevator in moving with constant velocity, thus

a = 0

 t = $\sqrt{\frac{2h}{g}}$ = $\sqrt{\frac{2 \times 2.45}{9.8}}$ = $\frac{1}{\sqrt{2}}$s