Answer:
20 J
Explanation:
Given:
Weight of the book is, 
Height or displacement of the book is, 
The work done on the book to raise it to a height of 2 m on a shelf is against gravity. The gravitational force acting on the book is equal to its weight. Now, in order to raise it, an equal amount of force must be applied in the opposite direction.
So, the force applied by me should be equal to weight of the body and in the upward direction. The displacement is also in the upward direction.
Now, work done by the applied force is equal to the product of force applied and displacement of book in the direction of the applied force.
Therefore, work done is given as:
Therefore, the work done to raise a book to a height 2 m from the floor is 20 J.
Answer:
Many familiar physical quantities can be specified completely by giving a single number and the appropriate unit. For example, “a class period lasts 50 min” or “the gas tank in my car holds 65 L” or “the distance between two posts is 100 m.” A physical quantity that can be specified completely in this manner is called a scalar quantity. Scalar is a synonym of “number.” Time, mass, distance, length, volume, temperature, and energy are examples of scalar quantities.
Answer:
What is the power of focus from the eye when a subject looks from 20 to 500 from its eye?
Explanation:
Is that your question?
Answer:
A. The closest point in the Moon's orbit to Earth
Explanation:
The perigee is defined as the closest point in the orbit of an object (such as a satellite) from the centre of the Earth. In this case, the Earth's satellite is the Moon, so the perigee is defined as the closest point in the Moon's orbit to Earth. so option A is the correct one.
Let's see instead the names of the other options:
B. The farthest point in the Moon's orbit to Earth --> this point is called apogee
C. The closest point in Earth's orbit of the Sun --> this point is called perihelion
D. The Sun's orbit that is closest to the Moon --> this point has no specific name
Thermal energy from the coffee is transferred to the mug.
