Answer:

Explanation:
Let say the empty wagon has mass "M"
now by newton's II Law we will have

now it is given that empty wagon is pulled with acceleration 1.4 m/s/s
now we will have

now a child of mass three times the mass of wagon is sitting on the empty wagon
so here we have


so we have

Question
What was the initial momentum of the bullet before collision?
Answer:
10 Kg.m/s
Explanation:
Momentum is a product of velocity of an object in m/s and its mass in kgs hence numerically expressed as p=mv where p is momentum, v is velocity and m is mass. Substituting m for 0.2 kg and v for 50 m/s then p=0.2*50=10 kg.m/s
A gram molecule<span> of a </span>gas<span> at </span>127<span>°C </span>expands isothermally until its volume<span> is </span>doubled<span>. </span>Find<span> the </span>amount<span>of </span>work done<span> and </span>heat absorbed<span>.</span>