Answer:

Explanation:
Given:
- wavelength of light in the air,

- time taken to travel from the source to the photocell via air,

- time taken to reach the photocell via air and glass slab,

- thickness of the glass slab,

<u>Now we have the relation for time:</u>

hence,

c= speed of light in air



For the case when glass slab is inserted between the path of light:
(since light travel with the speed c only in the air)
here:
v = speed of light in the glass


Using Snell's law:



Answer:
5.3×10⁴ m/s
Explanation:
From the question,
Momentum = mass× velocity
M = mV................ Equation 1
Where M = momentum of the airplane, m = mass of the airplane, V = Velocity of the airplane
make V the subject of the equation
V = M/m.................. Equation 2
Given: M = 1.6×10⁹ Kg.m/s, m = 3.0×10⁴ kg
Substitute these values into equation 2
V = 1.6×10⁹/3.0×10⁴
V = 5.3×10⁴ m/s
Answer:

Given:
Initial velocity (u) = 30 m/s
Final speed (v) = 0 m/s
Acceleration (a) = - 1.5 m/,s²
To Find:
Time in which train will come to rest (t).
Explanation:

So,
Time in which train will come to rest = 20 seconds
Answer:
Correct answer: Fg = m · g
Explanation:
Newton's second law states that if a resultant force is applied to an object, the object begins to move at an accelerated rate.
The formula that presents this is:
F = m · a
this formula applies to an object moving on some surface
where m is the mass of the object and a the acceleration of the object
Let's take it now and watch the free fall:
The formula that presents this is:
Fg = m · g
this formula applies to an object moving at free fall in vertical direction
Free fall is also an accelerated movement to which Newton's second law applies.
where m is the mass of the object and g the gravitation acceleration of the object . We also know that g is equal:
g = γ · Me / d² where Me is mass of the earth
God is with you!!!