Question

On a frictionless, horizontal air table, puck A (with mass 0.25 kg) is moving toward puck B (with mass 0.35 kg), which is initially at rest. After the collision,puck A has a velocity of 0.12 m per s to the left, and puck B has a velocity of 0.65 m per s to the right.

a.what is speed of puck A before collision?

Answer 1

The speed of puck A before the collision can be found using the principle of conservation of momentum. After performing the calculations, the speed of puck A before the collision is determined to be 0.79 m/s.

Step-by-step explanation:

The question is asking for the speed of puck A before the collision on a frictionless, horizontal air table. To find this, we use the conservation of momentum, which states that the total momentum before the collision is equal to the total momentum after the collision.

Let's define our system with puck A having mass mA = 0.25 kg and puck B having mass mB = 0.35 kg. The speed of puck A before the collision is what we'll call vAi, and the velocities after the collision are known: puck A is 0.12 m/s to the left and puck B is 0.65 m/s to the right.

Applying conservation of momentum:

• mA × vAi + mB × 0 = mA × (-0.12 m/s) + mB × (0.65 m/s)

Solving for vAi:

vAi = (mA × (-0.12 m/s) + mB × (0.65 m/s)) / mA

vAi = ((0.25 kg) × (-0.12 m/s) + (0.35 kg) × (0.65 m/s)) / (0.25 kg)

vAi = (-0.03 + 0.2275) kg × m/s / 0.25 kg

vAi = (0.1975 kg × m/s) / 0.25 kg

vAi = 0.79 m/s

Therefore, the speed of puck A before the collision was 0.79 m/s.