Answer:
7. I and III only.
Explanation:
Only portions of the electromagnetic spectrum is visible to the human eye. Electromagnetic radiation in this range of wavelengths is called visible light which have wavelengths from about 390 to 750 nm that is; ultraviolet light and visible light.
Answer:
The Acceleration will increase
Explanation:
Newton's Second Law of motion: It states that the rate of change of momentum is directly proportional to the applied force and takes places along the direction of the force.
It can be expressed mathematically as,
F ∝ m(v-u)/t
Where (v-u)/t = a
F = kma.
F = force, m = mass of the body, a = acceleration, k = constant of proportionality which tend to unity for a unit force, a unit mass, and a unit acceleration.
Therefore,
F = ma.
From the equation above,
If the net force acting on a body increase, while the mass of the body remains constant, the acceleration will also increase.
Explanation:
Work done is given by the product of force and displacement.
Case 1,
1. A boy lifts a 2-newton box 0.8 meters.
W = 2 N × 0.8 m = 1.6 J
2. A boy lifts a 5-newton box 0.8 meters.
W = 5 N × 0.8 m = 4 J
3. A boy lifts a 8-newton box 0.2 meters.
W = 8 N × 0.2 m = 1.6 J
4. A boy lifts a 10-newton box 0.2 meters.
W = 10 N × 0.2 m = 2 J
Out of the four options, in option (2) ''A boy lifts a 5-newton box 0.8 meters'', the work done is 4 J. Hence, the greatest work done is 4 J.
Answer:
A. 12,240.
Explanation:
1,530 times 8.0 = 12,240.
hope this helped :)
