What is a frame of reference? How is it used to measure motion?

An expression that uses operands of different data types is called a __________. a. composite expression b. compound expression c. mixed-type expression d. compound-type expression

Describe the motion of the following objects if they are observed from the stated frames of reference: a ball dropped by a boy walking at a speed of 1 m/s viewed by the boy

Which of the following best describes a fictitious force? (a) an apparent force used to explain the motion of objects within an inertial frame of reference (b) an apparent force used to explain the motion of objects within a non-inertial frame of reference (c) a real force that appears to act in the opposite direction because of the motion of the frame of reference (d) a force that is imaginary when observed in a non-inertial frame of reference but real when observed in an inertial frame of reference

Describe the motion of the following objects if they are observed from the stated frames of reference: a train traveling north viewed by a person standing on a platform

Is an n-type semiconductor actually negatively charged?

Why is it necessary to choose a single frame of reference when measuring motion?

Why is identifying the frame of reference important in describing motion?

Would you measure the height of a building in meters? Give reasons for your answer.

Find the velocity in meters per second of a swimmer who swims exactly 110 m toward the shore in 72 s.

A small airplane is flying at 50 m/s toward the east. A wind of 20 m/s toward the east suddenly begins to blow and gives the plane a velocity of 70 m/s east. Which vector is the resultant vector?

A person standing at the edge of a seaside cliff kicks a stone over the edge with a speed of 18 m/s. The cliff is 52 m above the water’s surface, as shown at right. How long does it take for the stone to fall to the water? With what speed does it strike the water?

Suppose G is a disconnected graph with N vertices, M edges and no circuits. (a) How many components does the graph have when N=9 and M=6? (b) How many components does the graph have when N=240 and M=236? Explain your answer.

Methane enters a 3-cm ID pipe at $30^{\circ} \mathrm{C}$ and 10 bar with an average velocity of 5.00 m/s and emerges at a point 200 m lower than the inlet at $30^{\circ} \mathrm{C}$ and 9 bar. a) Without doing any calculations, predict the signs $(+\mathrm{or}-)$ of $\Delta \dot{E}_{\mathrm{k}} \text { and } \Delta \dot{E}_{\mathrm{p}}$, where $\Delta$ signifies (outlet - inlet). Briefly explain your reasoning. b. Calculate $\Delta \dot{E}_{\mathrm{k}} \text { and } \Delta \dot{E}_{\mathrm{p}}$ (W), assuming that the methane behaves as an ideal gas. c) If you determine that $\Delta \dot{E}_{\mathrm{k}} \neq-\Delta \dot{E}_{\mathrm{p}}$, explain how that result is possible.