Answer :
Answer:
Radius of hill = r = 48 m
Explanation:
Given data:
Initial height = [tex]h_{1}[/tex] = 35 m
Final height = [tex]h_{2}[/tex] = 23m
Radius = r = ?
We know that
Change in potential energy = ΔP.E = mg(Δh)
ΔP.E = mg([tex]h_{2}[/tex] - [tex]h_{1}[/tex])
ΔP.E = mg(35 - 23)
ΔP.E = 12 mg
We know that
Change in Kinetic Energy = ΔK.E = 0.5 mv²
According to energy of conservation
ΔK.E = ΔP.E
0.5 mv² = 12 mg
v² = 24 g Eq 1
As she feels an apparent weight which is one-half of her normal weight
So,
Apparent weight = 0.5 normal weight
mg - mv²/r = 0.5 mg
0.5 g = v²/r
v² = 0.5 gr Eq 2
Compare Eq 1 and Eq 2
0.5 gr = 24 g
r = 48 m