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 (63.63 KiB) Viewed 14 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 DO 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? [4 marks] e) What modelling assumptions have you made in performing the above analyses? [3 marks]