A person is sitting in a car which is at rest. The reaction from the road at each of the four wheels of the car is R. When the car runs on a straight level road, how will the reaction at either of the front wheels vary?

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Submitted by examrobotsa on

Q: 127 (IAS/2008)
A person is sitting in a car which is at rest. The reaction from the road at each of the four wheels of the car is R. When the car runs on a straight level road, how will the reaction at either of the front wheels vary?

question_subject: 

Science

question_exam: 

IAS

stats: 

0,12,22,13,5,12,4

keywords: 

{'front wheels': [0, 0, 1, 0], 'reaction': [1, 0, 5, 18], 'straight level road': [0, 0, 1, 0], 'wheels': [1, 0, 2, 1], 'car': [0, 2, 12, 17], 'road': [1, 2, 5, 6]}

The question asks how the reaction force (force exerted back on an object when it exerts a force upon a surface) at each of the front wheels will vary when the car drives straight on a level road.

Option 1 suggests the reaction force will be greater than when the car is at rest. This would only be the case if there is an additional vertical force acting on the car, such as going uphill or carrying extra load.

Option 2 posits the reaction will be less than R. This would be correct in a scenario where a vertical force is reducing, such as if the car were going downhill or losing load.

Option 3 states the reaction will be equal to R. This is the correct answer. On a level, straight road with no change in vertical forces, the reaction force should not change and thus equals R.

Option 4 claims it depends on the road`s material. While the road material can affect friction and traction, it does not directly change the vertical reaction force.