Question

(a) Give an example of different net external forces acting on the same system to produce different accelerations. (b) Give an example of the same net external force acting on systems of different masses, producing different accelerations. (c) What law accurately describes both effects? State it in words and as an equation.

Short answer

(a) The example is applying the force of different magnitudes on the bodies having the same mass with different acceleration.

(b) The example is the application of the same force on two bodies with different masses will have different acceleration.

(c) Both the above examples follow Newton’s law of motion.

Step-by-step solution

(a) Example of different net forces acting on the same system producing different accelerations

An example is the application of force of magnitude, say 20 N, to a crate on the floor, which causes the crate to accelerate. When the greater force of magnitude, say 30 N force, is applied to the same crate, there is an increase in acceleration of the crate.

(b) Example of same net forces acting on systems with different masses producing different accelerations

An example is the application of force of magnitude, say 20 N, to a sled of mass, say 60 kg, which causes the sled to accelerate. When the same force of 20 N force is applied to another sled of mass, say 40 kg, there is an increase in acceleration of the sled.

Step 2: (c) Law describing both the above effects

The law that describes both the above effects is Newton’s Second Law of Motion, which states that the acceleration of a system is proportional to the net external forces acting on the system and inversely proportional to the system's mass.

Mathematically,

$a=\frac{F_{net}}{m}$

Here${}^a$is the acceleration,${}^m$is the mass, andlocalid="1654169557320" ${}^{F_{net}}$is the net force.