Question

Lacie kicks a football from ground level at a velocity of 13.9 m/s and at an angle of 25.0° to the ground. How long will the ball be in the air before it lands?

Round your answer to the nearest tenth.

Answer 1

The 1st one is 1.2 and the Second one is 15.1

Step-by-step explanation:

Just did it on Quiz and got it correct.

Answer 2

Just consider the vertical component

`d_y=v_(0,y)t+(1)/(2)at^2`

`d_y=(13.9\sin 25\°)t+(1)/(2)(-9.8~m/s^2)t^2 \\ \\ d_y=5.87t-4.9t^2`

Set d_y equal to 0 to find the times the ball is on the ground

`0=5.87t-4.9t^2 \\ \\ 0=t(5.87-4.9t) \\ \\ t=0 \\ \\ t=1.2~s`

The ball was in the air for 1.2 seconds