Question

a bullet shot straight ' returns to its starting point in 10 seconds . its initial speed was ?​

Answer 1

Explanation:

Use the Linear Motion equation for displacement:

s = ut + 1/2at^2

The displacement (s) of the particle is 0m since it returns to its original position, the time taken (t) is 10s and the acceleration due to gravity acting [downward] on the object is -9.81 m/s^2 [taking the upward direction as positive]. Sub all this into the equation to get:

0 = u(10) + 1/2(-9.81)(10)^2

0 = 10u - 490.5

Now rearrange to get:

490.5 = 10u

And finally take the 10 across to get:

u = 490.5/10

u = 49.05 m/s

Answer 2

Answer:

reversing is the answer friends and mark me as a brainlish answer