Let the mass of 2500 kg car be 
and it's velocity be 
and the mass of 1500 kg car be 
and it's velocity be 
.
After the bumping the mass be M and it's velocity be V.
By law of conservation of momentum we have
2500 * 5 + 1500 * 1=4000 * V
V = 14000/4000 = 7/2 = 3.5 m/s
So the velocity of the two-car train = 3.5 m/s
Answer:
The answer is B.
Explanation:
If 212 degrees Fahrenheit is 100 degrees Celsius, then 32 degrees Fahrenheit is 0 degrees Celsius.
Answer: Option (c) is the correct answer.
Explanation:
When a penny is dropped from a height of 20 meters then it will achieve an acceleration.
As acceleration is the rate of change in velocity of an object with respect to time. Therefore, the velocity does not remain constant.
Whereas mass of the penny will remain the same as it will not get affected when it falls. Also, there will be no change in direction of the penny as it is falling only in one direction.
The acceleration of penny is due to the force of gravity.
Thus, we can conclude that the force of gravity causes it to accelerate.
