Answer:
Answer D: It describes the relationship between motion and force.
Explanation:
The answer is D because a law is something that describes something in nature, but does not try to explain how or why is occurs (that is a theory). Options B and C sound more like theories, while option A sounds like a definition. Option D is correct because a law describes without explaining.
Answer:

Explanation:
In this question we have given

we have to find

We know that
optical path difference for bright fringe is given as
Here,
n is order of fringe
and optical path difference for dark fringe is given as
since the light with wavelength
produces its third-order bright fringe at the same place where the light with wavelength
produces its fourth dark fringe
it means
optical path difference for 3rd order bright fringe= optical path difference for forth order dark fringe
Therefore,
...............(1)
Put value of
in equation (1)



Given that,
Mass of each washer = 4.9 g
We need to calculate the mass of two washers in kg
Using conversion of unit
Mass of each washer 
So, Mass of two washers is

Put the value of m


If 4 washer are attached to the spring
We need to calculate the applied force on the car
Using formula of force

Put the value into the formula


Hence, (i), The mass of two washers is 0.0098 kg.
(ii). The applied force on the car is 0.192 N.
Answer:
The acceleration of the ball is constant and equal to -9.81 m/s² (acting downwards)
The velocity of the ball reduces at a constant rate with time on its way up
Explanation:
The motion of the ball upwards is described by the following equation;
v = u - g × t
v² = u² - 2 × g × s
Where;
v = The final velocity of the ball
u = The initial velocity of the ball
g = The acceleration due to gravity = Constant
s = The height of the bass after a given time, t
t = The time in which the ball is rising
Therefore, the acceleration of the ball = The acceleration due to gravity (Constant) = -9.81 m/s²↓
From v = u - g × t = u - 9.81 × t , the velocity of the ball reduces at a constant rate with time on its way up.