Answer:
Alpha = ω^2 R where R is radius of blade
g = w^2 r where r is distance from center
ω^2 R = 11.5 ω^2 r
R / r = 11.5 / 9.8 = 1.17
Or r = .852 R
Since the angular acceleration depends on both R and ω it seems that one can only get r as it depends on R
The answer to this question is d because prejudices is not based on experience or reasons
Power = (energy) divided by (time)
Answer:
0.95 seconds
Explanation:
t = Time taken
u = Initial velocity = 15 m/s
v = Final velocity
s = Displacement
a = Acceleration = 9.81 m/s² (downward positive, upward negative)
Time taken by the ball to reach the maximum height

Maximum height

Distance between maximum height of the ball and the branch is 11.47-7 = 4.46 m
So, the distance that will be covered on the way down is 4.46 m
Now
u = 0
s = 4.46

Time taken by the ball from the maximum height to the tree branch is 0.95 seconds.
Total time taken from the moment the ball is thrown to reach the tree branch is 1.52+0.95 = 2.47 seconds
Answer:
a) KA = 1.2 J
b) vB = 5.00 m/s
c) W = 6.30 J
Explanation:
m = 0.600 kg
vA = 2.00 m/s
KB = 7.50 J
a) KA = ?
b) vB = ?
c) W = ?
We can apply the folowing equations
K = 0.5*m*v²
and
W = ΔK = KB- KA
then
a) KA = 0.5*m*vA² = 0.5*(0.600 kg)*(2.00 m/s)²
⇒ KA = 1.2 J
b) KB = 0.5*m*vB² ⇒ vB = √(2*KB / m)
⇒ vB = √(2*7.50 J / 0.600 kg)
⇒ vB = 5.00 m/s
c) W = ΔK = KB- KA = (7.50 J) - (1.2 J)
⇒ W = 6.30 J