Answer
i'm not 100% sure but 1764
Explanation:
Work done = gravitational potential energy
Gravitational potential energy = mass(kg) × height(m) × gravitational field strength(N/kg)
We can assume that the student is on earth so the gravitational field strength is 9.8N/kg
So work done = 60 × 3×9.8
=1764
(if you need help calculating power but if you do just divide your answer by 12 and you will get 147)
The correct choice is Buffers.
Buffers contains both acids and bases in equilibrium.when base is added to buffers, they adjust the pH value by releasing hydrogen ions.when acid is added to buffers, they adjust the pH value by consuming hydrogen ions. hence these substances resist any change in their pH value by releasing or absorbing hydrogen ions.This process keeps the pH value constant.
<span>Jet streams act as an invisible director of the atmosphere and are largely responsible for changes in the weather across the globe.
Hope this helps</span>