Answer:
The Normal and Gravitational Force
Explanation:
The normal force pushes up and is between the ground and the scale. The gravitational force is the force exerted on the ground.
Answer:
option 4
Explanation:
Light's velocity in air ( 3 × 10^8 m/s ) is much greater than sound's velocity in air ( 343 m/s )
Hence due to difference in velocities , during lightning light is seen first & sound is heard later
Explanation:
Young' modulus is the ratio of normal stress to the longitudinal strain. Mathematically, it is given by :
Normal stress is given by force per unit area. Longitudinal strain is the change in length per unit original length.
The mathematical definition of Young's modulus is given by :
..........(1)
Where
is the change in length
F is the force
A is the area of cross section
So, the Young's modulus refers to the change in length of the object. Hence, the correct option is (b) "length".
Answer:
These are the two statements with scientific facts that explain the described phenomenon
<span>
Gravitation between two objects increases when the distance between them decreases.</span>
When the mass of an object increases, its gravitational pull also increases.
Justification:
Those two facts are represented in the Universal Law of Gravity discovered by the scientific Sir Isaac Newton (1642 to 1727) and published in his book <span>Philosophiae naturalis principia mathematica.</span>
That law is represented by the equation:
F = G × m₁ × m₂ / d²
The product of the two masses on the numerator accounts for the fact that the gravitational force is directly proportional to the product of the masses, which is that as the masses increase the attraction also increase.
The term d² (square of the distance that separates the objects) in the denominator accounts for the fact that the gravitational force is inversely proportional to the square of the distance; that is as the separation of the objects increase the gravitational force decrease.
