###### College Physics

386 SOLVED PROBLEMS

Question: 2.2

## SLOWLY MOVING TRAIN GOAL Obtain average and instantaneous velocities from a graph. PROBLEM A train moves slowly along a straight portion of track according to the graph of position vs. time in Figure 2.7a. Find (a) the average velocity for the total trip, (b) the average velocity during the first ...

(a) Find the average velocity from Ⓞ to ©. Calcula...
Question: 14.AP.6

## WHY DOES THE PROFESSOR SOUND LIKE DONALD DUCK? A professor performs a demonstration in which he breathes helium and then speaks with a comical voice. One student explains, “The velocity of sound in helium is higher than in air, so the fundamental frequency of the standing waves in the mouth is ...

The second student is correct. The fundamental fre...
Question: 16.11

## A PAPER-FILLED CAPACITOR GOAL Calculate fundamental physical properties of a parallel-plate capacitor with a dielectric. PROBLEM A parallel-plate capacitor has plates 2.0 cm by 3.0 cm. The plates are separated by a 1.0-mm thickness of paper. Find (a) the capacitance of this device and (b) the ...

(a) Find the capacitance of this device. Substitut...
Question: 8.14

## THE FALLING BUCKET GOAL Combine Newton’s second law with its rotational analog. PROBLEM A solid, uniform, frictionless cylindrical reel of mass M=3.00 kg and radius R=0.400 m is used to draw water from a well (Fig. 8.28a). A bucket of mass m=2.00 kg is attached to a cord that is wrapped around the ...

(a) Find the tension in the cord and the accelerat...
Question: 8.13

## WARMING UP GOAL Find a moment of inertia and apply the rotational analog of Newton’s second law. PROBLEM A baseball player loosening up his arm before a game tosses a 0.150−kg baseball, using only the rotation of his forearm to accelerate the ball (Fig. 8.27). The forearm has a mass of 1.50 kg and ...

(a) Find the angular acceleration of the ball. The...
Question: 2.7

## THE ACELA: THE PORSCHE OF AMERICAN TRAINS GOAL Find accelerations and displacements from a velocity vs. time graph. PROBLEM The sleek high-speed electric train known as the Acela (pronounced “ah cel’ la”) is currently in service on the Washington-New York-Boston run. The Acela consists of two power ...

(a) Describe the motion. From about −50 \ma...
Question: 2.5

## CAR CHASE GOAL Solve a problem involving two objects, one moving at constant acceleration and the other at constant velocity. PROBLEM A car traveling at a constant speed of 24.0 m/s passes a trooper hidden behind a billboard, as in Figure 2.17. One second after the speeding car passes the billboard ...

(a) How long does it take the trooper to overtake ...
Question: 2.3

## CATCHING A FLY BALL GOAL Apply the definition of instantaneous acceleration. PROBLEM A baseball player moves in a straight line path in order to catch a fly ball hit to the outfield. His velocity as a func tion of time is shown in Figure 2.11a. Find his instantaneous acceleration at points ...

Acceleration at Ⓐ. The acceleration at Ⓐ equals th...
Question: 17.AP.2

## LIGHTBULB FAILURES Why do lightbulbs fail so often immediately after they’re turned on? ...

The wipers are part of an $R C$ circu...