Please explain the steps you take and if you could draw a diagram, that would be
ID: 1659409 • Letter: P
Question
Please explain the steps you take and if you could draw a diagram, that would be great. Thank you.
Problem 10 A mother, Tina, and her daughter, Annie, are shopping in the supermarket, with Annie standing in the shopping cart. The combined mass of Tina, Annie, and the cart's contents is 80 kg. Tina is pushing the cart with a constant velocity of 0.2 m/s whe n they go down the cereal aisle, at which point Annie reaches up and pulls 3 boxes of Cheerios off the shelf and into the cart. (i)If the mass of one box of Cheerios is 1.3 kg, what would be the velocity of the cart after the cereal falls in? (ii)Tina has lightning-quick reflexes and responds in the same amount of time it takes for the cereal to collide with the cart. If her response time if 0.2 s, then what is the force she must exert on the cart to maintain a constant velocity?Explanation / Answer
i) By momentum conservation,
(80+1.3*3)v = 80*0.2
v = 80*0.2/83.9
= 0.1907 m/s
ii) Force = momentum change /time = (83.9*0.2-80*0.2)/0.2
= 3.9*0.2/0.2
= 3.9 N answer