A coin is gently dropped from a height of 20 m. If its velocity increases uniformly at the rate of 10 $m / s^{2}$ , with what velocity and after what time will it strike the ground?

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A lead ball is dropped into a lake from a diving board 5 m above the water hits the water with certain velocity and then sinks to the bottom with the same constant velocity. If it reaches the bottom in 3s after it is dropped the depth of the lake is

The correct option is D 20 mv2=u2+cosv=(0+2×10×5)1/2=(100)1/2v=10 m/sv=utan10=0+10×tt=15this is which ball is us lake,=(3−1)sec=2 secso, Depth =10×2=20 m

A lead ball is dropped into a lake from a diving board $5 m$ above the water hits the water with certain velocity and then sinks to the bottom with the same constant velocity. If it reaches the bottom in $3 s$ after it is dropped the depth of the lake is

The correct option is D $20 m$
$v^{2} = u^{2} + cos$
$v = (0 + 2 \times 10 \times 5)^{1 / 2}$
$= (100)^{1 / 2}$
$v = 10 m / s$
$v = u tan$
$10 = 0 + 10 \times t$
$t = 15$
this is which ball is us lake,
$= (3 - 1) s e c$
$= 2 s e c$
so, Depth $= 10 \times 2 = 20 m$