Answer:
The ball is in the air for 3.5 seconds
The initial horizontal component of velocity is 28.6 m/s
The vertical component of the final velocity is 34.3 m/s downward
The final velocity is 44.7 m/s in the direction 50.2° below the horizontal
Explanation:
A ball is thrown horizontally
That means the vertical component of the initial velocity ![u_{y}=0](https://tex.z-dn.net/?f=u_%7By%7D%3D0)
The initial velocity is the horizontal component ![u_{x}](https://tex.z-dn.net/?f=u_%7Bx%7D)
The ball is thrown from the top of a 60 m
That means the vertical displacement component y = 60 m
→ y =
t +
gt²
where g is the acceleration of gravity and t is the time
y = -60 m , g = -9.8 m/s² , ![u_{y}=0](https://tex.z-dn.net/?f=u_%7By%7D%3D0)
Substitute these values in the rule
→ -60 = 0 +
(-9.8)t²
→ -60 = -4.9t²
Divide both sides by -4.9
→ 12.2449 = t²
Take √ for both sides
∴ t = 3.5 seconds
* <em>The ball is in the air for 3.5 seconds </em>
The initial velocity is the horizontal component ![u_{x}](https://tex.z-dn.net/?f=u_%7Bx%7D)
The ball lands 100 meter from the base of the building
That means the horizontal displacement x = 100 m
→ x =
t
→ t = 3.5 s , x = 100 m
Substitute these values in the rule
→ 100 =
(3.5)
Divide both sides by 3.5
→
= 28.57 m/s
<em>The initial horizontal component of velocity is 28.6 m/s</em>
The vertical component of the final velocity is ![v_{y}](https://tex.z-dn.net/?f=v_%7By%7D)
→
=
+ gt
→
= 0 , g = -9.8 m/s² , t = 3.5 s
Substitute these values in the rule
→
= 0 + (-9.8)(3.5)
→
= -34.3 m/s
<em>The vertical component of the final velocity is 34.3 m/s downward</em>
The final velocity v is the resultant vector of
and ![v_{y}](https://tex.z-dn.net/?f=v_%7By%7D)
→ Its magnetude is ![v=\sqrt{(v_{x})^{2}+(v_{y})^{2}}](https://tex.z-dn.net/?f=v%3D%5Csqrt%7B%28v_%7Bx%7D%29%5E%7B2%7D%2B%28v_%7By%7D%29%5E%7B2%7D%7D)
→ Its direction ![tan^{-1}\frac{v_{y}}{v_{x}}](https://tex.z-dn.net/?f=tan%5E%7B-1%7D%5Cfrac%7Bv_%7By%7D%7D%7Bv_%7Bx%7D%7D)
→
= 28.6 ,
= -34.3
Substitute this values in the rules above
→ ![v=\sqrt{(28.6)^{2}+(-34.3)^{2}}=44.66](https://tex.z-dn.net/?f=v%3D%5Csqrt%7B%2828.6%29%5E%7B2%7D%2B%28-34.3%29%5E%7B2%7D%7D%3D44.66)
→ Its direction ![tan^{-1}\frac{-34.3}{28.6}=-50.18](https://tex.z-dn.net/?f=tan%5E%7B-1%7D%5Cfrac%7B-34.3%7D%7B28.6%7D%3D-50.18)
The negative sign means the direction is below the horizontal
<em>The final velocity is 44.7 m/s in the direction 50.2° below the horizontal</em>