Question

1. identify whether the following scenarios involve balanced (b) or unbalanced (u) forces.

a. ___ a car stopped at a red light.
b. ___ a ball rolling down a hill.
c. ___ an airplane flying at constant speed at the same altitude in one direction.
d. ___ an airplane taking off.
e. ___ a person sitting motionless on a chair.
f. ___ a person running at constant speed around a circular - path.

Explanation:

Step1: Understand balanced and unbalanced forces

Balanced forces: Net force is zero, no change in motion. Unbalanced forces: Net force is non - zero, change in motion.

Step2: Analyze each scenario

• a. A car stopped at a red light

The car is at rest. No change in motion. So, balanced forces (B).

• b. A ball rolling down a hill

The ball is accelerating (changing its speed as it goes down the hill). So, unbalanced forces (U).

• c. An airplane flying at constant speed at the same altitude in one direction

Constant speed and same altitude (no vertical or horizontal acceleration). Net force is zero. So, balanced forces (B).

• d. An airplane taking off

The airplane is accelerating (increasing its speed) to take off. So, unbalanced forces (U).

• e. A person sitting motionless on a chair

At rest. No change in motion. So, balanced forces (B).

• f. A person running at constant speed around a circular track

Although speed is constant, the direction is changing (circular motion). Velocity (a vector quantity, which includes direction) is changing. So, unbalanced forces (U).

Answer:

a. B, b. U, c. B, d. U, e. B, f. U