Question

Assertion: When astronauts throw something in space, that object would continue moving in the same direction and with the same speed. Reason: The acceleration of an object produced by a net applied force is directly related to the magnitude of the force and inversely related to the mass of the object.

Answer 1

Answer:

The reason and assertion is correct because the force is applied on the object is directly proportional to the mass of the object

Answer 2

Answer:

The assertion is correct, the reason is also correct, but the reason is not the correct explanation of the assertion.

Explanation:

Assertion:

Here it is given that when an astronaut throws something in space then that object will be moving in the same direction and with the same speed.

• The explanation for the assertion is in space there is no force present.   Forces like gravity, air resistance or buoyancy are absent.
• Newton's First Law states "if a body is at rest or moving at a constant speed in a straight line, it will remain at rest or keep moving in a straight line at constant speed unless it is acted upon by a force." we can say that the object will move in the same direction at the same speed, as there is no force present.
• From these points, we can say that the assertion is correct.

Reason:

In the "reason", it is given that the acceleration of a moving body is directly proportional to the net force acting on the body and inversely proportional to the mass of the body.

• To write the statement given in "reason" mathematically, let's take 'a' to be the acceleration of the body. From Newton's 2nd Law we have,

                                        $\^F=m\^a\\\^a=\frac{\^F}{m}$

where 'F' is the net force acting on the body and 'm' mass of the body.

• Taking only the magnitudes, we have,

                                       $a=\frac{F}{m}$

• From the above equation, we can write

                                      $a\propto F \\a\propto \frac{1}{m}$

• Therefore, the reason is also correct.

Here we can see that the assertion is correct, the reason is correct but the explanation given for the assertion is different from the reason.