Answer: The average velocity is 150 km/h
Explanation: 70+80=150
Answer:
The red ball has a greater kinetic energy, because it has a greater mass
Explanation:
Mass is directly proportional to kinetic energy, as one increases, so does the other
Answer:
A.
Explanation: both triple by 3
Answer:
A. The momentum of car A(5kg) is EQUAL to that of car B(0.5)
Explanation:
The moment, or impulse formula of the same forces acting on both car within 1 second is
![\Delta p = F * \Delta t](https://tex.z-dn.net/?f=%5CDelta%20p%20%3D%20F%20%2A%20%5CDelta%20t)
In our case the forces are the same, the time duration of force acting on the cars are the same. Therefore, their momentum right after the force must also be the same.
Considering conservation of momentum;
m1v1 + m2v2 = m3v3
In which,
m1 = mass of snowball 1 = 0.4 kg
v1 = velocity of snowball 1 = 15 m/s
m2 = mass of snowball 2 = 0.6 kg
v2 = velocity of snow ball 2 = 15 m/s
m3 = combined mass = 1 kg
v3 = velocity after comination
Therefore;
0.4*15 + 0.6*15 = 1*v3
v3 = 6+9 = 15 m/s
KE = 1/2mv^2
Then,
KE1 = 1/2*0.4*15^2 = 45 J
KE2 = 1/2*0.6*15^2 = 67.5 J
KE3 = 1/2*1*15^2 = 112.5 J
Therefore, KE3 (kinetic energy after collision) = K1+K2 {kinetic energy before collision). And thus it is 100%.