KE=3070.625 J
Height = 3.686 m
<h3>Further explanation</h3>
mass of bike+rider=85 kg
velocity = 8.5 m/s

Conservation of energy :
(KE+PE)₁ (downhill) = (KE+PE)₂ (up the hill)
PE₁=0⇒h=0
KE₂=0⇒v=0(stop), so equation becomes :
KE₁=PE₂

Answer: A) ionic salt
Explanation: Chlorine has a high electronegativity of 3.0. Copper like most metals has a low electronegativity, So the bonding is ionic making the compound an ionic salt.
The answer should be A. Because the energy in gasoline is called chemical. When burned it is heat, Then to power a vehicle, it is mechanical energy. But I don't know whether the question wants to mean that the energy in the gasoline will not convert totally to the heat, so it will lose. But if think like this, when heat energy transform to mechanical, it will lose again. So I think the answer is A.