Acceleration down a frictionless incline
A block slides down a frictionless ramp inclined at 30° above the horizontal. Using g = 10 m/s², what is its acceleration?
Answer A: explanation for every choice
A
Correct. Only gravity's component along the ramp accelerates the block: a = g sin 30° = 10 × 0.5 = 5 m/s².
B
This uses g cos 30°, the component perpendicular to the ramp.
C
This is free-fall acceleration, ignoring the ramp's angle.
D
This divides g by sin 30° instead of multiplying.
TakeawayAlong a frictionless incline: a = g sin θ.
Equation usedNewton's second law
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