A Machine Gun Is Attached to a Railroad Flatcar That

question 29

Multiple Choice

A machine gun is attached to a railroad flatcar that rolls with negligible friction.If the railroad car has a mass of 7 × 10⁴ kg,how many bullets of mass 20 g would have to be fired at 200 m/s off the back to give the railroad car a forward velocity of 0.5 m/s?

• A) 8.8
• B) 0.11
• C) 1,400
• D) 8,750
• E) ​14

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Definitions:

Salvage Value

The anticipated remaining worth of an asset when it reaches the end of its operational lifespan.

Net Present Value

The difference between the present value of cash inflows and the present value of cash outflows over a period of time.

Discount Rate

The interest rate used in discounted cash flow analysis to determine the present value of future cash flows.

Working Capital

The difference between a company’s current assets and current liabilities, indicating the short-term financial health and operational efficiency.