Answer:
The speed of the car when load is dropped in it is 17.19 m/s.
Explanation:
It is given that,
Mass of the railroad car, m₁ = 16000 kg
Speed of the railroad car, v₁ = 23 m/s
Mass of additional load, m₂ = 5400 kg
The additional load is dropped onto the car. Let v will be its speed. On applying the conservation of momentum as :



v = 17.19 m/s
So, the speed of the car when load is dropped in it is 17.19 m/s. Hence, this is the required solution.
The distance that light moves in a year is called a light year.
2) Light-year.
Answer:
this may be wrong but I am not sure
Answer:
a true
Explanation:
Water has the high specific heat capacity.
That means it resists to change its temperature when a considerable amount of heat lost or gained
4200J is needed to raise the temperature of 1kg substance by 1 degree Celsius
Answer:
1. 23°
2. 65°
Explanation:
1.
The law of reflection provides that for the same medium, the angle of reflection equals the angle of incidence.
Similarly, here, angle of incidence and reflection will be 46°÷2=23°
2. Since the normal, angles of reflection and incidence lie on the same plane and also the angles of reflection and incidence are equal then the angle between the plane of the mirror and the reflected beam will be given by 90-25=65°