The force of gravity between two objects is increased when the mass of objects is increased.
According to the conservation of mechanical energy, the kinetic energy just before the ball strikes the ground is equal to the potential energy just before it fell.
Therefore, we can say KE = PE
We know that PE = m·g·h
Which means KE = m·g·h
We can solve for h:
h = KE / m·g
= 20 / (0.15 · 9.8)
= 13.6m
The correct answer is: the ball has fallen from a height of 13.6m.
Momentum = mass x velocity
Before collision
Momentum 1 = 2 kg x 20 m /s = 40 kg x m/s
Momentum 2 = 3 kg x -10m/s = -30 kg x m/s
After collision
Momentum 1 = 2 kg x -5 m/s = -10 m/s
Momentum 2 = 3 kg x V2 = 3V2
Total momentum before = total momentum after
40 + -30 = -10 + 3V2
V2 = <span>6.67 m/s
Total kinetic energy before
</span><span>= (1/2) [ 2 kg * 20 m/s * 2 + 3 kg * ( -10 m/s) *2 ]
= 550 J
</span>
<span>Total kinetic energy after
</span>= (1/2) [ 2 kg * ( - 5 m/s) * 2 + 3 kg * 6.67 m/s *2 ]
= 91.73 J
Total kinetic energy lost during collision
=<span>550 J - 91.73 J
= 458.27 J</span>
Complete question is;
Which action would increase the strength of the electric force between the balloon and the water?
A. Holding a magnet near the stream of water
B. Holding the balloon closer to the stream of water
C. Holding a magnet near the balloon
D. Moving the balloon farther away from the stream of water
Answer:
B. Holding the balloon closer to the stream of water
Explanation:
When we take a charged balloon near water, what happens is that it makes electrons to be pushed away which in turn leaves the area to be positively charged. This area is now attracted to the balloon and thus the strength of the electric force between the balloon and the water is increased.
