Question

A hiker stands on the edge of a cliff 490 m above the ground and throw a stone horizontally with the initial speed of 15 m/s.neglecting air resistance .find the time taken by the stone to reach the ground and the speed by which it hits the ground given that he is equal to 9.8 m/s^2

Answer 1

Answer:

10 sec

Step-by-step explanation:

Initial velocity in horizontal direction=15m/s

Height, s= 490m

Horizontal velocity will not effect the velocity in vertical direction

Initial vertical velocity, u= 0m/s

Let final velocity at which the stone will hit the ground be v

Hence, it is a free fall motion in vertical direction

Applying the equation v²=u²+2as  (s=9.8m/s²)

v=√2as=√(2×9.8×490)=98m/s

The stone will hit the ground with 98m/s

now, applying the equation

v=u+at (t= time taken)

t=v/a=98/9.8=10 sec

The stone will hit he ground in 10 sec

Answer 2

Answer:

Time taken = root (2h/g)

=(2×490/9.8)

=10s

Speed is given in the question (15m/s)

Hope it helps.......

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