A force acts on a 3.0 g particle so that its position is x=3t-4t²+t³ (metres). Find work done during the first 4 s.
Options

Question

A force acts on a 3.0 g particle so that its position is x=3t−4t²+t³ (metres). Find work done during the first 4 s.

G1 Physics · Accepted Answer

Step 1 — Principle: The net work on a body equals its change in kinetic energy: Wₙₑₜ = Kf − Ki. Step 2 — Working: Velocity v=dx/dt=3−8t+3t². Step 3 — Working: Then v(0)=3 and v(4)=19 m/s. Step 4 — Working: Work=ΔK=½(.003)(19²−3²)=.528 J=528 mJ. Correct answer: D — 528 mJ.