Running the simulation

Procedure

1. Run the simulation with a final time of 4 seconds.

2. Plot the velocity of the car.

Figure 101: Velocity of the car

Note Initially the car runs backwards down the hill before the clutch begins to grip and it moves forwards. Perhaps you have failed your driving test?

3. Change the angle in MECMAS21 to –20 degrees.

4. Rerun the simulation.

5. Plot a graph of the velocity of the car and the rotary velocity of the engine. We now need to separate the axes to understand what is happening.

6. Right-click on the Y axis and select Separate:

Figure 102: Axis Format

What is happening? Figure 103: New curve of the velocity

Results

See if the situation can be cured by letting the clutch pedal up more slowly or by using more throttle (increase the engine torque).