Answer:
V1 =8.1 m/s
Explanation:
height at highest point (h2) = 4.1 m
height at lowest point (h1) = 0.8 m
acceleration due to gravity (g) = 9.8 m/s^{2}
from conservation of energy, the total energy at the lowest point will be the same as the total energy at the highest point. therefore
mgh1 +
= mgh2 + 
where
- speed at highest point = V2
- speed at lowest point = V1
- mass of the girl and swing = m
- at the highest point, the speed is minimum (V1 = 0)
- at the lowest point the speed is maximum (V2 is the maximum speed)
- therefore the equation becomes mgh1 +
= mgh2
m(gh1 +
) = m(gh2)
gh1 +
= gh2
V1 = 
now we can substitute all required values into the equation above.
V1 = 
V1 = 
V1 =8.1 m/s
Catastrophic events are sudden, natural or man-made, situations where change & destruction occur. All catastrophic events are the Earth's way of maintaining equilibrium during change.
Hi there!
Converting from angular velocity to tangential velocity can be done by:
v = ωr
v = tangential velocity (m/s)
ω = angular velocity (rad/sec)
r = radius (m)
Convert 12 cm to meters:
100 cm = 1 m
12 cm = 0.12 m
Now, convert rev/min to rad/sec:

v = 20.94 · 0.12 = 2.51 m/s