Question

A teenager decides it would be fun to “ride” a shopping cart in a parking lot as if it were a skateboard. He places the cart at rest in a parking lot, then runs up to it as fast as he can and jumps on.

Mass teenager = 65 kg , while speed = 45 km/hr= 0.28 m/s apprx

Momentum = mv = 65 ( 0,28) = 18.2 kg m/s

KE = 1/2 mv^2 = 0.5 ( 65) ( 0.28^2) =2,548 J before jumping on cart

D) Using these numbers estimate the speed of the cart just after the teenager jumps on. Show work

Answer 1

let the mass of the cart be mc . Initially cart was at rest

therefore, when the teenager will jump on the cart, the angular momentum along the horizontal direction will remain conserved (if we assume friction to be zero). therefore from the conservation of angular momentum

as initial momentum of cart is zero, and after jumping on the cart , both teen and the cart will move with the same velocity

therefore , putting the value of mc , we can find the common velocity of teen and cart (although mass of cart is not given in the question)