Class t Help Homework 7 Begin Date: 3/16/2018 9:00:00 AM-Due Date: 4/3/2018 11:5
ID: 2035477 • Letter: C
Question
Class t Help Homework 7 Begin Date: 3/16/2018 9:00:00 AM-Due Date: 4/3/2018 11:59.00 PM End Date: 4/3/2018 11:59:00 PM (89) Problem 10: A BB gun is fired at a cardboard box of mass 2-0. 75 kg on a frictionless surface. The BB has a mass of m- 0.0155 kg and travels at a velocity of v - 71 m's. It is observed that the box is moving at a velocity of v2- 0.11 m/s ater the BB passes through it 33% Part (a) write an expression for the magnitude of the BB's velocity as it exits the box Grade Summary Deductions Potential 10 718 9 HOME Submissions Attempts remainin per attempt) etailed view END 1m2 V1 V | BACKSPACE CLEAR Submit Hint 1 give up! Hines: deduction per hant Hints remaining: Feedback: deduction per feedback - ? 33% Part (b) what is the BB's final velocity vt, in meters per second? 33% Part (c) If the BB doesn't exit the box, what will the velocity of the box va be in meters per second?Explanation / Answer
mass of bb m1 = 0.0155 kg
mass of box m2 = 0.75 kg
initial velocity of bb u1 = 71 m/s
velocity of the box after the bb passes through it v2 = 0.11 m/s
a) from conservation of momentum
m1u1+m2u2 = m1v1+m2v2
v1 = (m1u1-m2v2)/m1
b) v1 = (0.0155*71-0.75*0.11)/0.0155
v1 = 65.68 m/s
c) if bb does not exit
m1u1 = (m1+m2)v
v = 0.0155*71/(0.0155+0.75) = 1.44 m/s