Answer:
The mass of the 500 series bullet train is 181.4 tonnes.
Explanation:
The momentum is given by:

Where:
m: is the mass =?
v: is the velocity = 261.8 km/h
p: is the momentum = 13194098.64 kg*m/s
By solving the above equation for "m" we have:

Therefore, the mass of the 500 series bullet train is 181.4 tonnes.
I hope it helps you!
Answer: (d)
Explanation:
Given
Mass of object 
Speed of object 
Mass of object at rest 
Suppose after collision, speed is v
conserving momentum

Initial kinetic energy

Final kinetic energy

So, it is clear there is decrease in kinetic energy . Thus, energy decreases and velocity becomes 2 m/s.
Answer:
freezing point and melting point

- P is power
- R is resistance

Hence


- Therefore if power is low then resistance will be high.
The first bulb has less power hence it has greater filament resistance.