Question

Question #84c1c

Answer 1

See the answer below...

Explanation:

When we throw a object on the sky it takes same time to go up as to go downwards...
Hence the object takes `color(red)(3.56/2=1.78s` to rise up or to rise down...
Refer you this for the formulas...

PROBLEM A

Now we have to determine the initial velocity`(v_i)` and we have final velocity `(v_f)` to be zero...
Hence,
`v_f=v_i-at` [Here the case of retardation i.e, negative acceleration]
`=>v_i=g t` [Here gravitational acceleration]
`=>v_i=10xx1.78=17.8ms^-1` That is the initial velocity

PROBLEM B

`v_f^2=v_i^2+2as` [s=DISPLACEMENT]
`=>v_i^2=2gs`
`=>17.8^2=2xx10xxs`
`=>s=15.842m`

Hope the answer helps...
Thank you...