Q1. A train is shown in figure Q1 below and consists of an engine of mass 20 tonnes and a set of coaches of mass 80 tonn

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Q1 A Train Is Shown In Figure Q1 Below And Consists Of An Engine Of Mass 20 Tonnes And A Set Of Coaches Of Mass 80 Tonn 1 (87.59 KiB) Viewed 11 times

Q1. A train is shown in figure Q1 below and consists of an engine of mass 20 tonnes and a set of coaches of mass 80 tonnes. The engine is linked to the coaches via a rigid coupling. When moving there is a constant rolling resistance of 30 N per tonne for both the engine and the coaches. In preparing to stop at a station, the brakes are applied generating a braking force of 50 kN at the engine and 60 kN from the coaches. The train is travelling over a straight and level track. Coupling Coaches Engine 80 tonne 20 tonne 00 Figure Q1: A train and coaches a) Construct a free body diagram considering the engine and coaches as a single body and hence, or otherwise, calculate the deceleration of the train. [7 marks] b) What coefficient of friction must be present between the engine wheels and the track in order to achieve this level of deceleration? [5 marks] c) Determine the load in the coupling between the engine and the coaches by constructing a free body diagram for either the engine or the coaches. [6 marks] d) If the train is travelling at a constant 50 ms¹ how many seconds before reaching the station does the driver need to apply the brakes and how far will the train travel in this time? e) What modelling assumptions have you made in performing the above analyses? [4 marks]