Which one of the following cannot be explained on the basis of Newton's third law of motion ?

Options

A. rowing of boat in a pond
B. motion of jet in the sky
C. rebounding of a ball from a wall
D. returning back of body thrown above

Answer

To determine which of the given options cannot be explained by Newton's third law of motion, we first need to understand what Newton's third law states. According to Newton's third law of motion, for every action, there is an equal and opposite reaction. This means that when one object exerts a force on another object, the second object exerts a force of equal magnitude but in the opposite direction back on the first object.

Now, let's analyze each option provided in the question:

1. **Rowing of a boat in a pond**: When a person rows a boat, they push the water backward with the oars. According to Newton's third law, the water pushes the boat forward with an equal and opposite force. Thus, this scenario can be explained by Newton's third law.

2. **Motion of a jet in the sky**: When a jet engine expels exhaust gases backward, it pushes against the air. The air, in turn, exerts an equal and opposite force on the jet, propelling it forward. This is also an example of Newton's third law in action.

3. **Rebounding of a ball from a wall**: When a ball strikes a wall, it exerts a force on the wall. The wall exerts an equal and opposite force on the ball, causing it to rebound. This is another example that can be explained by Newton's third law.

4. **Returning back of a body thrown above**: When a body is thrown upwards, it moves against the force of gravity. The force that causes it to return back to the ground is due to gravitational attraction, not due to an action-reaction pair as described by Newton's third law. This scenario does not involve two interacting objects exerting forces on each other in the way described by Newton's third law.

Based on this analysis, the correct answer is that the **returning back of a body thrown above** cannot be explained on the basis of Newton's third law of motion.

### Summary of Steps:
1. Understand Newton's third law of motion.
2. Analyze each option to see if it involves action-reaction pairs.
3. Conclude which option does not fit the criteria of Newton's third law.