Question

A projectile is launched from ground level at an angle of 30.0° above horizontal with a speed of 30.0 m/s. If the projectile is moving over level ground, how long is it in the air before it again contacts the ground?​

Answer 1

Answer:

Time = 3 seconds

Explanation:

We need to find time period

So when the particle hits the ground again it will complete its journey

So the displacement in Y - Direction will be 0

By formula, S = ut + 1/2 gt^2

We get

0 = 15t + 1/2 (-10)t^2

0 = t(15 - 5t)

Here t = 0 and t = 3s

we get two values of t as it is at the ground when motion starts and when it ends.

So time period will be = 3 sec