Answer: 10(sin45 + 0.5 cos45).
- A 5 + 5/sqrt(2)
- B 10/sqrt(2) + 5
- C 10(sin45 + 0.5 cos45)
- D 5*sqrt(2)
Correct answer: C. 10(sin45 + 0.5 cos45)
Explanation: Deceleration going up = g(sin theta + mu cos theta) = 10(sin45 + 0.5 cos45) = 10 x 1.5/sqrt(2) = 15/sqrt(2) approx 10.6 m/s<sup>2.</sup>
Free-body diagram of a block on an incline: weight (mg) resolves into mg sinθ along the slope and mg cosθ into the slope, balanced by the normal force N and friction f.
Concept context
Newton's three laws, friction, circular motion, and free body diagrams.