Question

A ball is dropped from a balloon up to speed 10m/s if balloon was a height 40m at time of dropping the ball how long will the ball take time in reaching the ground ​

Answer 1

Answer:

Speed=7m/s

height=60m

So, initially, the ball is going the upward,

u=−7m/s,s=60m,a=g=10m/s

s=ut+21gt2

60=−7t+2110t2

5t2−7t−60=0

t=2×57±49+4×5×60

t=107±35.34

Taking +ve sign then we get,

t=107±35.34=4.2s

Thus,  the ball will take time  in reaching the ground  is:

4.2s

Answer 2

Given,

Speed=7m/s

height=60m

So, initially, the ball is going the upward,

u=−7m/s,s=60m,a=g=10m/s

2

s=ut+

2

1

gt

2

60=−7t+

2

1

10t

2

5t

2

−7t−60=0

t=

2×5

7±

49+4×5×60

t=

10

7±35.34

Taking +ve sign then we get,

t=

10

7±35.34

=4.2s

Thus, the ball will take time in reaching the ground is:

4.2s