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.
RELATED QUESTIONS
A girl weighing 25 kg stands on the tloor. She exerts a downward force of 250 N on the floor. What force does the floor exert on her ?
If a man jumps out from a boat, the boat moves backwards. Why ?
Explain why, when a fireman directs a powerful stream of water on a fire from a hose pipe, the hose pipe tends to go backward.
Complete a sentence and explain it.
The working of a rocket depends on Newton's ______ law of motion.
While catching a cricket ball the fielder lowers his hands backwards. Why?
According to the third law of motion, action and reaction
Consider a frame that is made up of two thin massless rods AB and AC as shown in the figure. A vertical force `vec"P"` of magnitude 100 N is applied at point A of the frame.
Suppose the force is `vec"P"` resolved parallel to the arms AB and AC of the frame.
The magnitude of the resolved component along the arm AC is xN.
The value of x, to the nearest integer, is ______.
[Given: sin(35°) = 0.573, cos(35°) = 0.819, sin(110°) = 0.939, cos(110°) = –0.342]
In a hose pipe ejecting water, what is the reaction force?
Can action and reaction forces be noncontact forces?
What is the main characteristic of action and reaction forces?
