Practical: weight component down an incline
G5.3
By the end of this lesson you should be able to
- Investigate the parallel component of the weight of an object down an inclined plane at various angles. G5.3
Key ideas
- Aim: investigate how the parallel component of weight changes with incline angle (G5.3).
- IV: angle (set by height h and ramp length l, \(\sin\theta = h/l\)). DV: force to hold the object still (spring balance or force sensor). Controlled: mass, surface.
- Analysis: plot F against sin θ. The model predicts a straight line through the origin with gradient mg.
- Evaluate: friction, reading the spring balance, measuring small angles.
Key formulas (QCAA formula book notation)
\[
F_\parallel = m g \sin\theta \Rightarrow \text{gradient} = m g
\]
Common mistakes
- Pulling the spring balance at an angle to the slope.
- Not zeroing the force meter.
Do
- Read: Textbook (Oxford Physics for Queensland Units 3 & 4) section 3.4
- Do: Practical 3.4 questions
- Data skills: Data test skills and practice
Try it
Further reading
- OpenStax Physics 5.4 Inclined planes (OpenStax, CC BY 4.0)
- Full topic notes: Gravity & Motion