13 - Experimental Methods and Comprehensive Review Free Online FlashCards

What is the first step in the Physics Problem-Solving Cycle?

First define the system, then describe the situation, choose a model, create a representation, write a symbolic relationship, solve, check, and communicate the conclusion.

What belongs on a free-body diagram?

A free-body diagram includes only forces acting on the selected object. It should not include velocity, acceleration, or forces that the object exerts on other objects.

What do slope and area mean on a velocity-versus-time graph?

For a velocity-versus-time graph, the slope represents acceleration and the area under the graph represents displacement.

When is a kinematics model appropriate?

Use kinematics when acceleration is known or can be treated as constant, without needing to analyze the forces causing the motion.

Can momentum be conserved when kinetic energy is not?

Momentum may be conserved when the net external impulse is negligible, even if kinetic energy is not conserved. Kinetic energy is conserved only in elastic interactions.

What condition relates translation and rotation in rolling without slipping?

For rolling without slipping, the center-of-mass speed and acceleration satisfy $v_{\text{cm}}=\omega R$ and $a_{\text{cm}}=\alpha R$.

What determines the period of a mass–spring oscillator?

For a mass–spring oscillator, $T=2\pi\sqrt{\frac{m}{k}}$. Its period is independent of amplitude only within the small-amplitude approximation for an ideal oscillator.

What changes when a wave enters a new medium?

When a wave enters a new medium, its frequency generally remains fixed because the source sets it. The wavelength changes as the wave speed changes, according to $v=f\lambda$.

How do independent and dependent variables differ?

The independent variable is deliberately changed; the dependent variable is measured in response. Other important quantities should be controlled.

How do random and systematic effects differ?

Random effects cause trial-to-trial scatter and can be reduced by repetition and averaging. Systematic effects shift measurements consistently, so repetition alone does not remove them.

How is uncertainty propagated for a sum or difference?

For addition or subtraction, approximate absolute uncertainties add: $\delta q\approx\delta a+\delta b$. For multiplication or division, approximate fractional uncertainties add.

How can spring-period data be linearized?

Plotting $T^2$ versus mass $m$ linearizes the spring-period model $T^2=\left(\frac{4\pi^2}{k}\right)m$. The slope is $\frac{4\pi^2}{k}$.