Question

A 62 kg man holds an 13 kg bag of potatoes as he rides in a 40 kg cart traveling at 0.50 m/s along flat ground. He throws the bag of potatoes from the cart in the direction of the cart's velocity which brings the cart to a stop. What was the speed of his throw?

A. 0.50 m/s

B. 2.9 m/s

C. 2.0 m/s

D. 4.4 m/s

Answer 1

Mass of the man = m₁ = 62 kg

Mass of the cart = m₂ = 40 kg

Mass of the bag of potatoes = m₃ = 13 kg

Speed the cart with the man and the bag of potatoes is travelling with initially = V₁ = 0.5 m/s

Speed of the cart with the man after the man throws the bag of potatoes = V₂ = 0 m/s (Stops)

Speed of the bag of potatoes after the throw = V₃

By conservation of linear momentum,

(m₁ + m₂ + m₃)V₁ = (m₁ + m₂)V₂ + m₃V₃

(62 + 40 + 13)(0.5) = (62 + 40)(0) + (13)V₃

V₃ = 4.4 m/s

Speed of the throw = 4.4 m/s