Question

Two objects of mass 0.2 kg and 0.1 kg, respectively, move parallel to the xaxis, as shown above. the 0.2 kg object overtakes and collides with the 0.1 kg object. immediately after the collision, the ycomponent of the velocity of the 0.2 kg object is 1 m/s upward. what is the ycomponent of the velocity of the 0.1 kg object immediately after the collision'?

Answer 1

Two pucks moving on a frictionless air table are about to collide, as shown. The 1.5 kg puck is movingdirectly east at 2.0 m/s. Two objects of mass 0.2 kg and 0.1 kg, respectively, move parallel to the x-axis,as shown on Immediately after the collision, the y-component of the velocity of the 0.2 kg object is 1 m/s upward.

Answer 2

Answer: the velocity in the y component is -2m/s

Explanation: Here we must apply the conservation of the linear momentum.

In the initial scenario, both objects move in the x-direction, so the total momentum in y is equal to zero because momentum is Py = m*vy

In this scenario, we only have momentum in x, but that does not matter in this problem.

Now, after the collision, the object of m = 0.2kg, has a velocity in y of vy1 = 1m/s, then the momentum of this object is Py1 = 0.2kg*1m/s = 0.2kg*m/s

Now we apply the conservation, before the impact we have that the total momentum in y is zero, so we have now that:

Py1 + Py2 = 0 = 0.2kg*m/s + Py2

and Py2 = 0.1kg*vy2

0.1kg*vy2 = 0.2kg*m/s

vy1 = -(0.2kg*m/s)/(0.1kg) = -2m/s