Answer:
1800J
Explanation:
Given parameters:
Weight of the book = 20N
Total distance covered = 45m + 15m + 30m = 90m
Unknown:
Total work performed on the books = ?
Solution:
To solve this problem we must understand that work done is the force applied to move a body through a certain distance.
So;
Work done = Force x distance
Work done = 20 x 90 = 1800J
Answer
given,
mass of steel ball, M = 4.3 kg
length of the chord, L = 6.5 m
mass of the block, m = 4.3 Kg
coefficient of friction, μ = 0.9
acceleration due to gravity, g = 9.81 m/s²
here the potential energy of the bob is converted into kinetic energy



v = 11.29 m/s
As the collision is elastic the velocity of the block is same as that of bob.
now,
work done by the friction force = kinetic energy of the block




d = 7.23 m
the distance traveled by the block will be equal to 7.23 m.
Answer:
(θ) = 60°
Explanation:
Given:
Speed of canoe Vc = 2 m/s
Speed of River Vr = 1 m/s
Computation:
Vc (Cosθ) = Vr
2 (Cosθ) = 1
(Cosθ) = 1 / 2
(Cosθ) = (Cos60)
(θ) = 60°
Answer:
AM radio, FM radio, microwaves, sodium light.
Explanation:
Electromagnetic radiation are waves from electromagnetic field which spread through the space or any other material medium and carries radiating energy. Examples includes X rays, radio waves, Gamma rays, etc. Exposure to high level of electromagnetic radiation could be harmful to human body, on the other hand, science as not been able to prove that exposing humans to low level electromagnetic radiation is harmful to our health.