The rate of change of momentum of an object is equal to the … A) impulse on the object - NSC Physical Sciences - Question 1 - 2020 - Paper 1

The gravitational acceleration 'g' can be calculated using the formula:

$$g = \frac{G M}{r^2}$$

For planet Y, with mass 2M and radius (\frac{r}{2}), the expression for gravitational acceleration becomes:

$$g' = \frac{G(2M)}{\left(\frac{r}{2}\right)^2} = \frac{G(2M)}{\frac{r^2}{4}} = \frac{8GM}{r^2} = 8g$$

Hence, the answer is:

D) 8g.

Given that the graph shows how one of the physical quantities associated with an object in free fall changes with time and knowing that in free fall, the only quantity that linearity with time can occur is velocity, we conclude:

The graph likely indicates that the physical quantity represented on the y-axis can be consistent with velocity measurements, as position would produce a nonlinear representation on a time graph.

Thus, the correct answer is:

A) Velocity.