Answer:
Because china was in war, and her parents didn't have enough money for to go to school.
Uhhhh...you should have paid attention in class, just saying...
You are given a fixed rate of 15.9 cm³/s. You are also given with the amount of volume in 237 cm³. Through the approach of dimensional analysis, you can manipulate through operations such that the end result of the units must be in seconds. The solution is as follows:
237 cm³ * (1 s/15.9 cm³) = 14.9 seconds
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.
Answer:
6.21 m/s
Explanation:
Using work energy equation then
where d is displacement from initial to final position, v is velocity and subscripts a and b are position A and B respectively, m is mass of collar, g is acceleration due to gravity
Substituting 1 Kg for m, 0.4m for h, 
as 0, 9.81 for g then
