4.2. Rolling Resistance

Try these first

1. 1.

   What is rolling resistance?

   Hint

   Think about how different surfaces impact moving vehicles.

2. 2.

   Why might a crawler machine be selected over a wheeled machine?

   Hint

   Consider the type of terrain where each machine performs best.

3. 3.

   What is rolling resistance influenced by?

   • Terrain type
   • Contract specifications
   • Both

   Hint

   Think about what aspects affect machinery performance.

4. 4.

   True or False: Higher altitude generally results in better machinery performance due to less air density.

   • True
   • False

   Hint

   Consider how altitude changes affect engine operation.

5. 5.

   Calculate the power requirement for a machine moving over a rocky surface. If the rolling resistance coefficient is 0.05 and the weight of the truck is 10,000 kg, how much power is needed to maintain a speed of 10 m/s?

   Hint

   Remember to calculate force using the rolling resistance coefficient and the weight.

6. 6.

   You have two machines: a wheeled loader rated at 150 horsepower and a crawler loader at 200 horsepower. The wheeled loader struggles to maintain speed on a muddy terrain while the crawler performs efficiently. Discuss the implications of machine selection based on rolling resistance.

   Hint

   Think about the relationship between horsepower and terrain conditions.