Question

An aeroplane flying 490m above the ground level at 100m/s releases a block how far on the ground will it strike

Answer 1

Time taken by block to fall = sqrt(2H/g)
= sqrt(2 * 490 / 9.8)
= 10 s

Horizontal distance travelled by block
= Speed × Time
= 100 × 10
= 1000 m
= 1 km

It will fall 1km far from ground.

Answer 2

The aeroplane is flying 490m above the ground.

The speed of aeroplane in will be the speed of block in horizontal.

The downward speed of block will be zero.

By using the formula H=ut +(1/2)gt^2 for vertical motion....

H=490m

u=0 (initial velocity in vertical direction of block)

g=9.8m/s^2

t=?

490= 0 + (9.8/2)t^2

490=4.9t^2

t^2=100

t= 10sec (because time is always +ve)

We have time taken by block to reach the ground. we also have velocity of block in horizontal direction. So we can find distance in Horizontal direction(Range).

As displacement= velocity×time

Range = 100×10

Range=1000m