Question

Please help :/ The same motor is used in rockets with different masses. The rockets have different accelerations. According to Newton’s second law, how is acceleration expected to change as the rocket mass increases?
Acceleration cannot be predicted based on changes in mass.
As rocket mass increases, acceleration decreases.
As rocket mass increases, acceleration increases.
There are no changes in acceleration, as it would depend on the amount of force. _

Different amounts of force are applied to the same boat over several trials, and the acceleration is measured. In a graph of acceleration versus net force, what does the slope of the graph represent?
the speed of the boat _
the mass of the boat _
the inverse of the mass of the boat _
the inverse of the speed of the boat

Answer 1

Answer:

1. As rocket mass increases, acceleration decreases.

2. The inverse of the mass of the boat.

Explanation:

1. Newton's second law of motion states;

         F = ma

where F is the force applied, m is the mass and a is the acceleration.

Therefore, increasing the mass of a rocket increases its weight which would reduce its acceleration provided that the force is constant. Thus, as rocket mass increases, acceleration decreases.

2. The slope of the graph can be expressed as;

From Newton's second law,

F = ma

Slope = (Δa) ÷ (ΔF)

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

⇒ $\frac{1}{m}$ = $\frac{a}{F}$

Therefore, the slope of the graph is the reciprocal of the mass of the boat.