Advertisements
Advertisements
Question
According to the third law of motion, when we push on an object, the object pushes back on us with an equal and opposite force. If the object is a massive truck parked along the roadside, it will probably not move. A student justifies this by answering that the two opposite and equal forces cancel each other. Comment on this logic and explain why the truck does not move.
Advertisements
Solution
- The truck has a big bulk. As a result, the truck's static friction with the road is extremely high.
- To move the car, one must exert more force than static friction. As a result, when someone pushes the vehicle and it does not move, the imparted force in one direction is balanced by an equivalent amount of frictional force operating in the opposing direction.
- As a result, moving the vehicle requires a significant amount of imbalanced force.
- As a result, the student is correct in claiming that the two opposite and equal concepts cancel each other out.
APPEARS IN
RELATED QUESTIONS
Explain, why is it difficult for a fireman to hold a hose, which ejects large amounts of water at a high velocity.
Is the following statement true or false :
A rocket can propel itself in a vacuum.
What is the force which produces an acceleration of 1 m /s2 in a body of mass 1 kg ?
Why does a gunman get a jerk on firing a bullet ?
If action is always equal to reaction, explain why a cart pulled by a horse can be moved.
Do action and reaction act on the same body or different bodies ? How are they related in magnitude and direction ? Are they simultaneous or not ?
Explain why, a runner presses the ground with his feet before he starts his run.
Draw a diagram to show how a rocket engine provides a force to move the rocket upwards. Label the diagram appropriately.
According to the third law of motion, action and reaction
Why do the action and reaction forces in a pair not cancel each other out?
