C4. A 50.0 kg boy runs at 10.0 m/s, jumps on a cart and rolls off at 2.50 m/s. What is the mass of the cart

The mass of the cart is 150 kg.

Explanation:

Given that,

Mass of a boy, m₁ = 50 kg

Initial speed of boy, u₁ = 10 m/s

Initial speed of car, u₂ = 0 (at rest)

The speed of the cart with the boy on it is 2.50 m/s, V = 2.5 m/s

Let m₂ is the mass of the cart. Using the conservation of momentum as follows :

So, the mass of the cart is 150 kg.

i think the answer is b

can be answered using momentum.

momentum = p

p1= mass1 * velocity1

p1 = p2

therefore

p1 = 6kg * 4m/s

p1 = 24kgm/s

p2=m2 * v2

24 kgm/s = 7kg * v2

v2 = 24 kgm/s / 7kg

v2= 3.42 m/s