Answer:
(a). The speed at the moment of being thrown is 30.41 m/s.
(b). The maximum height is 47.18 m.
Explanation:
Given that,
Weight of stone = 3.00 N
Height = 15 m
Speed = 25.0 m/s
(a). We need to calculate the speed at the moment of being thrown
Using work energy theorem
[tex]W=\dfrac{1}{2}m(v_{2}^2-v_{1}^2)[/tex]
[tex]-mg\times d=\dfrac{1}{2}m(v_{2}^2-v_{1}^2)[/tex]
Put the value into the formula
[tex]-9.8\times15=\dfrac{1}{2}\times(v_{2}^2-v_{1}^2)[/tex]
[tex]-2\times9.8\times15=25^2-v_{1}^2[/tex]
[tex]-v_{1}^2=-300-25^2[/tex]
[tex]v_{1}=\sqrt{925}[/tex]
[tex]v_{1}=30.41\ m/s[/tex]
(b). We need to calculate the maximum height
Using work energy theorem
[tex][tex]W=\dfrac{1}{2}mv_{2}^2-\dfrac{1}{2}mv_{1}^2[/tex]
[tex]mg\times d=\dfrac{1}{2}mv_{2}^2-\dfrac{1}{2}mv_{1}^2[/tex]
Here, [tex]\dfrac{1}{2}mv_{2}^2[/tex]=0
[tex]-(mg)\times d=\dfrac{1}{2}mv_{1}^2[/tex]
[tex]d=\dfrac{v_{1}^2}{2g}[/tex]
Put the value into the formula
[tex]d=\dfrac{30.41^2}{2\times9.8}[/tex]
[tex]d=47.18\ m[/tex]
Hence, (a). The speed at the moment of being thrown is 30.41 m/s.
(b). The maximum height is 47.18 m.
