Question

An ore cart of mass 1200 kg is rolling at a speed of 12.8 m/s across a flat surface. A crane dumps 338 kg of ore into the cart from directly above it. How fast does the cart move after being loaded with ore?

Answer 1

10.0 m/s

Step-by-step explanation

The ore cart has a mass m1 of 1200kg, and rolls at a speed v1 of 12.8 m/s. Then a crane dumps 338 kg of extra ore into the cart, so now the mass is m2 = m1 + 338 kg = 1538 kg. We want to find the new speed v2 of the ore cart.

By law of conservation of momentum we have:

`m_2v_2=m_1v_1_{}`

Solving for v2:

`v_2=(m_1v_1)/(m_2)`

And replacing with the values:

The speed of the ore cart is now 10.0 m/s, rounded to the nearest tenth