A stone is thrown vertically upwards with an intinal velocity of 20 m/sec . find the maximum height it reaches and the time by it reachthe height (g=10 m/sec).

Maximum height is20m and time taken will be 2second

Explanation:

vi=20m/s

vf=0m/s

g=10m/s^2

Using third equation for objects falling freely

2gh=(vf)^2-(vi)^2

Putting values

2(10m/s^2)h=(0m/s)^2-(20m/s)^2

20h=400m

h=20m

Now we have to find the time

Using first equation of motion for objects falling down freely

vf=vi+at

substituting the equation

(vf-vi)/g=t

(0-20)/10=t

t=2second

the answer would be c

b mirrors submit a iisner? e. for which optical devices does d sometimes have a positive value? o a a and b o b. a and c o c. b and d 0 d. b and cb