The answer would be A. Visible light only.
Answer:
No, the ball will not clear the fence.
Solution:
Angular velocity, 
Height, h = 1.2 m
Angle, 
Distance covered by the ball, d = 110 m
Length of the fence, l = 1.2 m
Radius of the axis, R = 46 cm = 0.46 m
Now,
To calculate the linear velocity of the ball, v:
Total time taken:
The distance at which the ball falls, with a = 0 is given by:
Since, the ball has to clear a fence 1.2 m long and a t a distance 110 m away, clearly it will not be able to cross it.
Answer:
An electromagnet is a magnet that runs on electricity. Unlike a permanent magnet, the strength of an electromagnet can easily be changed by changing the amount of electric current that flows through it. The poles of an electromagnet can even be reversed by reversing the flow of electricity.
Answer:
a) N = 7.90 10³ N, b) N = -1.04 10⁴ N
Explanation:
a) For this exercise we can use Newton's second law
N -W = m (-a)
The relationship is centripetal, the negative sign of the acceleration is because it points towards the center of the circle
a = v² / r
we substitute
N = mg -m v² /r
N = m (g - v² /r)
let's calculate
v = 8.7 m / s
N = 1240 (9.81 - 8.7²/22)
N = 7.90 10³ N
b) v = 20 m / s
N = 1240 (9.81 - 20²/22)
N = -1.04 10⁴ N
