A mysterious crate has shown up at your place of work, Firecracker Company, and

Question

A mysterious crate has shown up at your place of work, Firecracker Company, and you are told to measure its inertia. It is too heavy to lift, but it rolls smoothly on casters. Getting an inspiration, you lightly tape a 0.60-kg iron block to the side of the crate, slide a firecracker between the crate and the block, and light the fuse. When the firecracker explodes, the block goes one way and the crate rolls the other way. You measure the crate's speed to be 0.064 m/s by timing how long it takes to cross floor tiles. You look up the specifications of the firecracker and find that it releases 9 J of energy. That's all you need, and you quickly calculate the inertia of the crate.

Problem 5.56 A mysterious crate has shown up at your place of work, Firecracker Company, and you are told to measure its inertia. It is too heavy to lift, but it rolls smoothly on casters. Getting an inspiration, you tape a block to the side of the crate, slide a firecracker between the crate and the block, and light the fuse. When the firecracker explodes, the block goes one way and the crate rolls the other way. You measure the crate's speed to be 0.064 m/s by timing how long it takes to cross floor tiles. You look up the specifications of the firecracker and find that it releases 9 J of energy. That's all you need, and you quickly calculate the inertia of the crate. Part A What is that inertia? Express your answer with the appropriate units m Value kg Submit My Answers Give Up incorrect; Try Again; 4 attempts remaining

Explanation / Answer

Applying momentum conservation,

0.60 v - (m x 0.064) = 0

v = 0.1067 m ..........(i)

Applying energy conservation,

9 = ( 0.60 v^2 / 2 ) + ( m (0.064)^2 / 2)

18 = 0.60 x (0.1067 m )^2 +

18 = 0.00683 m^2 + 0.004906m

m = 51 kg

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.