Question

A stone is dropped from a building of height 30 it accelerates at a rate of 8 metre per second square what will be the velocity of the stone when it hits the ground how long will it take to reach the ground solve with the help of third equation of motion​

Answer 1

Answer:

When the stone is dropped, initial velocity = 0.

Now, h=(1/2)gt

2

Distance travelled in t

n

sec can be written as h

n

=(1/2)gt

n

2

Distance travelled in t

n

−1 sec can be written as h

n−1

=(1/2)g(t

n

−1)

2

So, h

n

−h

n−1

= journey in nth second = (1/2)g(t

n

2

−(t

n

−1)

2

)

=(1/2)g(2t

n

−1)=g(t

n

−1/2)

Now using h=(1/2)gt

2

for h = 45m we get t = 3 sec

So, in the 3rd second the stone will travel 10 X 2.5 m = 25 m.