A 15 kg mass, moving east at 5 m/s, collides elastically with another 10 kg mass, moving west at 1 m/s. After the collision, the larger mass moves off with a velocity of 3 m/s. What is the final velocity of the smaller mass?

Question

Is it 4m/s? Or would it be 2m/s?
Do you add the momentum of the 2 masses because of conservation of momentum or subtract them because they're going in different directions?

Answer 1

conservation of energy.

energy before= energy after
15*5^2+10*1^2=15*3^2+10*v^2
V^2= 1.5*25+1-1.5*9
v= 5m/s check the math.

Answer 2

A solenoid has a cross-sectional area of 5.80 10-4 m2, consists of 100 turns per meter, and carries a current of 0.6 A. A 10 turn coil is wrapped tightly around the circumference of the solenoid. The ends of the coil are connected to a 0.7 resistor. Suddenly, a switch is opened, and the current in the solenoid dies to zero in a time of 0.16 s. Find the average current induced in the coil.

Answer 3

What is the momentum of a car travelling at 65 m per second with a mass of 95,000 kg