Answer:
500 m
Explanation:
t = Time taken
u = Initial velocity = 50 m/s
v = Final velocity = 0
s = Displacement
a = Acceleration = -2.5 m/s²
Equation of motion

Time taken by the train to stop is 20 seconds

∴ The engineer applied the brakes 500 m from the station
Answer:
Light passes through the gas
Light passes through the pure water
Light passes through some solids
Explanation:
In gasses, there are many spaces between the molecules. These spaces allow light to pass through them without any interruption.
In pure water, there are some spaces between particles. these particles allow some light rays to pass theough, some to move through the common boundary and reflec5 some of them.
in solids, some allow light to pass through as they are transparent or translucent
Answer:

Explanation:
When the car is under an accelerating force and hits a tree, the instant force received by the tree is the same force that is accelerating the car.
The accelerating force can be calculated using Newton's second law:

Where m is the mass of the car and a is the acceleration.


Answer:
1. Friction enables us to walk freely.
2. It helps to support ladder against wall.
3. It becomes possible to transfer one form of energy to another.
4. Objects can be piled up without slipping.