Answer:
Explained below
Explanation:
A) Newton's first law of motion states that an object will remain at rest or continue in its current state of motion except it is acted upon by another force.
Now using this law, when you jump off the ground, the earth will move a tiny bit and accelerate due to the force applied by the jumping.
B) Newton's 2nd law states that the acceleration of a system is directly proportional to the net external force acting on that system, is in the same direction with it and also inversely proportional to the mass.
In this case, when one jumps, an external force is exerted on the earth and we are told it is directly proportional to the acceleration of the system which in this case it's the earth, then it means that there is some motion by the earth even though you didn't see it move.
C) Newton's third law of motion states that to every action, there is an equal and opposite reaction.
In this case the motion of the jumper will lead to an equal and opposite reaction of the earth.
Answer:
K.E = 0.0075 J
Explanation:
Given data:
Mass of the ball = 1.5 kg
radius, r = 50 cm = 0.5 m
Angular speed, ω = 12 rev/min = (12/60) rev/sec = 0.2 rev/sec
Now,
the kinetic energy is given as:
K.E = 
where,
I is the moment of inertia = mr²
on substituting the values, we get

or
K.E = 0.0075 J
This is easily explained saying that the frictional force between the books and the paper isn't big enough to produce a displacement in the books. The displacement in the books doesn't happen because the frictional force between the books and the surface they are standing on is bigger than the paper's one.
Answer: The HUMAN EYE
Explanation:
The human eye is made up of different parts which ranges from controlling the amount of light that enters the eye to the focusing of the image that is formed. The camera is a device which is both mechanically and electronically operated which shares a number of similarities with the eye.
In the human eye, the IRIS helps to regulate the amount of rays passing through the pupil to the lens by either contracting or dilating in light or dark environment respectively. While in the camera, the DIAPHRAGM controls the amount of light entering the camera.
The PUPIL serves as the passage for light into the eye while in the camera, the APERTURE does the same.
The photosensitive surface in the eye is the YELLOW SPOT while in the camera, the photosensitive surface is the PHOTOGRAPHIC FILM.