Answer:

Explanation:
Given:
- moment of inertia of the skater with extended arms,

- moment of inertia of the the skater with pulled-in arms,

- angular velocity of the skater with extended arms,

<u>Using the law of conservation of angular momentum:</u>



Radio waves have the lowest radiant energy, hope this helps :]
Answer:
Distance = 30 m
Explanation:
Since the position of the bus is at zero, and distance is a scalar quantity. That is, we are only concerned about the magnitude
If Angela ran to the bus and back to where she started, the distance travelled will be:
Distance = 15 + 15 = 30 m
But her displacement will be:
Displacement = 15 - 15 = 0.
It looks correct, but that graph only shows position and time?
Answer:
(A) The maximum height of the ball is 40.57 m
(B) Time spent by the ball on air is 5.76 s
(C) at 33.23 m the speed will be 12 m/s
Explanation:
Given;
initial velocity of the ball, u = 28.2 m/s
(A) The maximum height
At maximum height, the final velocity, v = 0
v² = u² -2gh
u² = 2gh

(B) Time spent by the ball on air
Time of flight = Time to reach maximum height + time to hit ground.
Time to reach maximum height = time to hit ground.
Time to reach maximum height is given by;
v = u - gt
u = gt

Time of flight, T = 2t

(C) the position of the ball at 12 m/s
As the ball moves upwards, the speed drops, then the height of the ball when the speed drops to 12m/s will be calculated by applying the equation below.
v² = u² - 2gh
12² = 28.2² - 2(9.8)h
12² - 28.2² = - 2(9.8)h
-651.24 = -19.6h
h = 651.24 / 19.6
h = 33.23 m
Thus, at 33.23 m the speed will be 12 m/s