Question

A 1000 kg dragon is at rest sleeping in outer space. A 50 kg unicorn runs into the dragon with a velocity of 600 ms . The final velocity of the dragon is 40 ms . What is the final velocity of the unicorn?

Answer 1

Step-by-step explanation:

This is a Law of Momentum Conservation problem where, in particular, our problem looks like this:

`[m_dv_d+m_uv_u]_b=[m_dv_d+m_uv_u]_a` in other words, the momentum before they collide has to be equal to the momentum after they collide. Knowing that the dragon is initially at rest:

[1000(0) + 50(600)] = [1000(40)m + 50v] and

0 + 30,000 = 40,000 + 50v and

-10,000 = 50v so

v = -200 m/s or

200 m/s in the direction opposite to its initial direction