Question

two forces act on a parachutist during a drop. one force is the weight (w) of the parachutist. the force is the upwards pull (p) from the parachute harness on the parachutist. the parachutist has a mass of 50kg. what is the acceleration of the parachutist? 17.8m/s² 0.5m/s² 4500m/s² 1.8m/s²

Explanation:

Step1: Find net force

Net force \( F_{net} = W - P \) (since W is downward and P is upward, assuming downward is positive).
\( F_{net} = 490N - 400N = 90N \) (downward).

Step2: Apply Newton's second law

Newton's second law: \( F = ma \), so \( a = \frac{F_{net}}{m} \).
Mass \( m = 50kg \), \( F_{net} = 90N \).
\( a = \frac{90N}{50kg} = 1.8m/s^2 \). Wait, but wait—wait, maybe I mixed directions. Wait, W is weight (downward), P is upward pull. So if W is 490N (downward) and P is 400N (upward), net force is \( 490 - 400 = 90N \) downward. Then \( a = F/m = 90/50 = 1.8m/s^2 \). Wait, but the options have 1.8? Wait, the options: 17.8, 0.5, 500, 1.8. Wait, maybe I made a mistake. Wait, weight \( W = mg \), so \( m = W/g = 490N / 9.8m/s^2 = 50kg \), which matches. Then net force: \( F_{net} = W - P = 490 - 400 = 90N \). Then acceleration \( a = F_{net}/m = 90/50 = 1.8m/s^2 \). So the answer is 1.8m/s².

Answer:

\( 1.8m/s^2 \) (corresponding to the option with 1.8m/s²)