Answer:
Final potential energy = 24 Joule
The velocity with which object must be thrown = [tex]4 \sqrt{10}[/tex] m/s
Step-by-step explanation:
Given:
Mass of object, m = 0.30 Kg
Height of object, h = 8 m
Acceleration due to gravity, g = 10 [tex]ms^{-2}[/tex]
a) Formula for Potential Energy:
[tex]E_p =mgh[/tex]
Where m is the mass of object
g is acceleration due to gravity and
h is the height of object
Putting the values of m, g and h
[tex]E_p = 0.3 \times 10 \times 8\\\Rightarrow E_p =24 J[/tex]
b) Formula for initial and final velocity:
[tex]v^{2} =u^{2} +2gh[/tex]
where v is the final velocity
u is the initial velocity with which the object is thrown
g is acceleration due to gravity and
h is the height obtained by object
here v = 0 at the height 8 m because it will come to rest at the point it attains the maximum height.
h = 8m
g = -10 [tex]ms^{-2}[/tex] (negative because the object's velocity is decreasing)
Putting the values to find 'u':
[tex]0^{2} =u^{2} +2 \times -10 \times 8\\\Rightarrow u^{2} = 160\\\Rightarrow u = 4 \sqrt{10}\ m/s[/tex]
