A)Ep'=mgh=mgl(1-cosa).At the bottom of the swing Ep=0(reference level),so the potential energy as the child is just released is bigger than the potential energy at the bottom of the swing.;B)The speed of the child at the bottom of the swing-->v=√(2gh)=√[2gl(1-cosa)];C)I don't think that the tension does any work.
Answer:
The 80 mph car
Because the formula says 1/2 mass but for the velocity it is squared
Answer: maximum height= 40.8m
Explanation: shown in the attachment.
Goodluck
Answer:
Explanation:
Horizontal displacement
x = 120 t
Vertical position
y = 3610 - 4.9 t²
y = 0 for the ground
0 = 3610 - 4.9 t²
t = 27.14 s
This is the time it will take to reach the ground .
During this period , horizontal displacement
x = 120 x 27.14 m
= 3256.8 m
So packet should be released 3256.8 m before the target.
It is a mechanical wave and cannot travel through a vacuum.