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**< Mentor Note -- Poster has been reminded to use the Homework Help Template and show their work on schoolwork problems >**

Hello everyone I have some questions on engine calculations that I need help in please.

1) A reciprocating internal combustion engine operates on a 4 stroke cycle. If the engine's crankshaft is rotating at 5,985 rev/min, calculate the number of engine cycles completed every second

(note that I tried 5985/60 and that gave me a wrong answer)

2) An engine has a crank radius of 41mm. If the engine's crankshaft is rotating at 2131 rev/min the calculate the mean piston speed (m/s)

3) For an engine:

-Operating at speed of 2151 rev/min

-Having a crank radius of 41 mm

-Having a connect a connecting rod length of 136 mm

When the crankshaft has rotated 84 degrees from top dead centre, calculate the velocity of the piston, u (m/s), in the x-axis direction.

(why isn't the velocity 0 m/s since the piston only move in the y axis?)

4) An engine has the following geometry:

-A bore of 75 mm

-A stroke of 70 mm

-A ratio of connecting rod length to crank radius of of 3.8 m/m

Calculate the rate of change of volume (m^3 / rad) when the crankshaft has rotated -30 degrees from top dead centre

Thank you in advance

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