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

im sorry i dont know

what experimental evidence led scientists to change from the previous model to this one?

a few of the positive particles aimed at a gold foil seemed to bounce back.

the colors of light emitted from heated atoms had very specific energies.

experiments with water vapor showed that elements combine in specific proportions.

cathode rays were bent in the same way whenever a magnet was brought near them.