Question

Two trolleys are moving in the same direction along a track. Trolley 1 has a momentum of 2 kg m/s and Trolley 2 has a momentum of 6 kg m/s. Trolley 2 catches up to Trolley 1. They collide, stick together and move off with a velocity of 2 m/s. Use the principle of conservation of momentum to work out the combined mass of the trolleys.

Answer 1

Answer:

Here is Your answer buddy!

Answer 2

The combined mass of the trolleys is 4 kg.

Explanation:

1. From conservation of momentum

 Total Initial momentum = Total final momentum  

 $m_{1}v_{1}+m_{2}v_{2}= (m_{1}+m_{2})\times V$   ...1)

2. In equation 1)

   $m_{1}v_{1}$ =initial momentum of trolley 1 = 2 $(\frac{kg m}{s})$        ...2)

    $m_{2}v_{2}$ =initial momentum of trolley 2 = 6 $(\frac{kg m}{s})$        ...3)

     $m_{1}+m_{2}$= combine mass of trolley 1 and 2

   V = final velocity of combine mass = 2$(\frac{m}{s})$      ...4)

3. So from equation 1)

    $m_{1}v_{1}+m_{2}v_{2}= (m_{1}+m_{2})\times V$

     2 +6= $(m_{1}+m_{2})\times 2$

   So

   $m_{1}+m_{2}$ =4 kg