A motorist is traveling at 20 mis. J{e is 60 m from a stop lightwhen he sees it turn

a. Write a paragraph describing the particle model. What is it, and why is it important? b. Give two examples of situations, different from those described in the text, for which the particle modeljs appropriate. c. Give an example of a situation, different from those described in the text, for which it would be inappropriate.

A softball player slides into second base. Use the particle model to draw a motion diagram of the player from the time he begins to slide until he reaches the base. Number the dots in order, starting with zero.

A car travels to the left at a steady speed for a few seconds, then brakes for a stop sign. Use the particle model to draw a motion diagram of the car for the entire motion described here. Number the dots in order, starting with zero.

A ball is dropped from the roof of a tall building and students in a physics class are asked to sketch a motion diagram for this situation. A student submits the diagram shown in Figure Q 1.4. Ts the diagram correct? Explain.

Write a sentence or two describing the difference between position and displacement. Give one example of each.

Give an example of a trip you might take in your car for which the distance traveled as measured on your car's odometer is not equal to the displacement between your initial and final positions.

Write a sentence or two describing the difference between speed and velocity. Give one example of each.

The motion of a skateboard along a horizontal axis is observed for 5 s. The initial position of the skateboard is negative with respect to a chosen origin, and its velocity throughout the 5 s is also negative. At the end of the observation time, is the skateboard closer to or farther from the origin than initially? Explain.

You are standing on a straight stretch of road and watching the motion of a bicycle; you choose your position as the origin. At one instant, the position of the bicycle is negative and its velocity is positive. Is the bicycle getting closer to you or farther away? Explain.

Two friends watch a jogger complete a 400 m lap around the track in I 00 s. One of the friends states, "The jogger's velocity was 4 mis during this lap." The second friend objects, saying, "No, the jogger's speed was 4 mis." Who is cotTect? Justify your answer.

A softball player hits the ball and starts running toward first base. Draw a motion diagram, using the particle model, showing her velocity vectors during the first few seconds of her run

A child is sledding on a smooth, level patch of snow. She encounters a rocky patch and slows to a stop. Draw a motion diagram, using the particle model, showing her velocity vectors.

A skydiver jumps out of an airplane. Her speed steadily increases until she deploys her parac hute, at which point her speed quickly decreases. She subsequently falls to earth at a constant rate, stopping when she lands on the ground. Draw a motion diagram, usi ng the particle model, that shows her position at successive times and includes velocity vectors.

Your roommate drops a tennis ball from a third-story balcony. It hits the sidewalk and bounces as high as the second story. Draw a motion diagram, using the particle model, showing the ball 's velocity vectors from the time it is released until it reaches the maximum height on its bounce

A car is driving north at a steady speed. It makes a gradual 90 left turn without losing speed, then continues driving to the west. Draw a motion diagram, using the particle model, showing the car's velocity vectors as seen from a helicopter hovering over the highway.

A toy car rolls down a ramp, then across a smooth, horizontal floor. Draw a motion diagram, using the particle model, showing the car's velocity vectors.

Density is the ratio of an object's mass to its volume. Would you expect density to be a vector or a scalar quantity? Explain .

student walks 1.0 mi west and then 1.0 mi north. Afterward, how far is she from her starting poi nt? A. 1.0 mi B. 1.4 mi C. 1.6 mi D. 2.0 mi

Which of the following motions could be described by the motion diagram of Figure Q 1.20? A. A hockey puck sliding across smooth ice. B. A cyclist braki ng to a stop. C. A sprinter starting a race. D. A ball bouncing off a wall.

Which of the following motions could be described by the motion diagram of Figure Q 1.20? A. A hockey puck sliding across smooth ice. B. A cyclist braki ng to a stop. C. A sprinter starting a race. D. A ball bouncing off a wall.

Which of the following motions is described by the motion diagram of Figure QI .21? A. An ice skater gliding across the ice. B. An airplane braking to a stop after landing. C. A car pulling away from a stop sign. D. A pool ball bouncing off a cushion and reversing direction.

A bird flies 3.0 km due west and then 2.0 km due north. What is the magnitude of the bird's displacement? A. 2.0 km B. 3.0 km C. 3.6 km D. 5.0 km

Weddell seals make holes in sea ice so that they can swim BIO down to forage on the ocean floor below. Measurements for one seal showed that it dived straight down from such an opening, reaching a depth of 0.30 km in a time of 5.0 min. What was the speed of the diving seal? A. 0.60 mis B. 1.0 mis C. 1.6 mis D. 6.0 mis E. 10 mis

A bird flies 3.0 knJ due west and then 2.0 km due north. Another bird flies 2.0 km due west and 3.0 km due nmth. What is the angle between the net displacement vectors for the two birds? A. 23 B. 34 C. 56 D. 90

A woman walks briskly at 2.00 mis. How much time will it take her to walk one mile? A. 8.30 min B. 13.4 min C. 2 1.7 mio D. 30.0 min

Compute 3.24 m + 0.532 m to the correct number of s ignificant figures. A. 3.7 m B. 3.77 m C. 3.772 m D. 3.7720 m

A rectangle has length 3.24 m and height 0.532 m. To the correct number of significant figures, what is its area? A. 1.72 m2 B. 1.723 1112 C. 1.7236 1112 D. 1.72368 m2

The eanh fom1ed 4.57 X 109 years ago. What is this time in seconds? A. 1.67 x !012 s c. 2.40 x !015 s B. 4.01 x 1013 s D. 1.44 x 1017 s

An obj ect's average density p is defined as the ratio of its mass to its volume: p = MI V. The earth's mass is 5.94 X 1024 kg, and its volume is 1.08 X 1012 km3. What is the earth's average density? A. 5.50 x 103 kg/m3 C. 5.50 x I 09 kg/m3 Section 1.3 Velocity B. 5.50 x 106 kglm3 D. 5.50 x 1012 kglm3

A circ ular test track for cars in England has a circumference of 3.2 km. A car travels around the track from the southernmost point to the northernmost point. a. What distance does the car travel? b. What is the car's displacement from its original position?

Migrating geese tend to travel at approximately constant BIO speed, flying in segments that are straight lines. A goose fli es 32 km south, then turns to fly 20 km west. Afterward, how far is the goose from its original position?

Black vultures excel at gliding flight; they can move long BIO distances through the air without flapping their wings while undergoing only a modest drop in height. A vulture in a typi cal glide in still air moves along a path tipped 3.5 below the horizontal. If the vulture moves a horizontal distance of 100 m, how much height does it lose?

A hiker walks 25 north of east for 200 m. How far north and how far east is he from his starting position?

A hiker is c limbing a steep 10 slope. Her pedometer shows that she has walked 1500 m along the slope. How much elevation has she gained?

A ball on a porch rolls 60 cm to the porch's edge, drops 40 cm, continues rolling on the grass, and eventually stops 80 cm from the porch's edge. What is the magnitude of the ball's net displacement, in centi meters?

A kicker punts a football from the very center of the field to the sideline 43 yards downfield. What is the net displacement of the bal l? (A football field is 53 yards wide.)

A squirrel completing a shott glide travels in a straight line BIO tipped 40 below the horizontal. The squirrel statts 9.0 m above the ground on one tree and glides to a second tree that is a horizontal distance of 3.5 m away. a. What is the length of the squirrel's glide path? b. What is the squirrel's height above the ground when it lands?

A squirrel in a typical long glide covers a horizontal distance BIO of 16 m while losing 8.0 m of elevation. During this glide, a. What is the angle of the squirrel's path below the horizontal? b. What is the total distance covered by the squirrel?

In a typical greyhound race, a dog accelerates to a speed of BIO 20 mis over a distance of 30 m. It then maintains this speed. What would be a greyhound's time in the 100 m dash?

Billy drops a watermelon from the top of a three-story building, 10 m above the sidewalk. How fast is the watermelon going when it hits?

Sam is recklessly driving 60 mph in a 30 mph speed zone when he suddenly sees the police. He steps on the brakes and slows to 30 mph in three seconds, looking nonchalant as he passes the officer. How far does he travel while braking?

A speed skater moving across frictionless ice al 8.0 mis hits a 5.0-ID-wide patch of rough ice. She slows steadily, then continues oi:i at 6.0 mis. What is her acceleration on the rough ice?

The giant e land, an African antelope, is an exceptional BIO jumper, able to leap 1.5 m off the ground. To jump this high, with what speed must the eland leave the ground?

A ball rolls along a sr:nooth horizontal floor at I 0 mis, then starts up a 20 ramp. How high does it go before rolling back down?

A motorist is traveling at 20 mis. J{e is 60 m from a stop light when he sees it turn yellow. His reactjon time, before stepping on the brake, is 0.50 s. What steady deceleration while braking will bring him to a stop right at the light?

Problems 46 through 50 show a motion diagram. For each of these problems, write a one or two sentence "story" about a real objec1 that has this motion diagram. Your stories should talk about people or objects by name and say what they are doing. Problems 39 through 45 are examples of motion short stories.

Problems 46 through 50 show a motion diagram. For each of these problems, write a one or two sentence "story" about a real objec1 that has this motion diagram. Your stories should talk about people or objects by name and say what they are doing. Problems 39 through 45 are examples of motion short stories.

Problems 46 through 50 show a motion diagram. For each of these problems, write a one or two sentence "story" about a real objec1 that has this motion diagram. Your stories should talk about people or objects by name and say what they are doing. Problems 39 through 45 are examples of motion short stories.

Problems 46 through 50 show a motion diagram. For each of these problems, write a one or two sentence "story" about a real objec1 that has this motion diagram. Your stories should talk about people or objects by name and say what they are doing. Problems 39 through 45 are examples of motion short stories.

Problems 46 through 50 show a motion diagram. For each of these problems, write a one or two sentence "story" about a real objec1 that has this motion diagram. Your stories should talk about people or objects by name and say what they are doing. Problems 39 through 45 are examples of motion short stories.

How many inches does light travel in one nanosecond? The speed of light is 3.0 x I08 mis.

Joseph watches the roadside mile markers during a long car trip on an interstate highway. He notices that at I0:45 AM they are passing a marker labeled I 0 I, and at I I :00 AM the car reaches marker 11 9. What is the car's speed, in mph?

Alberta is going to have dinner at her grandmother's house, but she is running a bit behind schedule. As she gets onto the highway, she knows that she must exit the highway within 45 min if she is not going to arrive late. Her exit is 32 mi away. What is the slowest speed at which she could drive and still arrive in time? Express your answer in miles per hour.

The end of Hubbard Glacier in Alaska advances by an average of I 05 feet per year. What is the speed of advance of the glacier in mis?

The earth completes a circular orbit around the sun in one year. The orbit has a radius of 93,000,000 miles. What is the speed of the earth around the sun in mis? Report your result using scientific notation

Shannon decides to check the accuracy of her speedometer. She adjusts her speed to read exactly 70 mph on her speedometer and holds th is steady, measuring the time between successive mile markers separated by exactly 1.00 mile. If she measures a time of 54 s, is her speedometer accurate? If not, is tbe s~eed it shows too high or too low?

The Nardo ring is a circular test track for cars. It has a circumference of 12.5 kID. Cars travel around the track at a constant speed of I 00 km/h. A car starts at the easternmost poi nt of the ring and drives for 15 minutes at this speed. a. What distance, in km, does the car travel? b. What is the magnitude of the car's displacement, in km, from its initial position? c. What is the speed of the car in mis?

Motor neurons in mammals transmit signals from the brain to BIO skeletal muscles at approximately 25 mis. Estimate how much time in ms ( I 0-3 s) it will take for a signal to get from your brain to your hand.

Satell ite data taken several times per hour on a paiticular BIO albatross showed travel of 1200 km over a time of 1.4 days. a. Given these data, what was the bird's average speed in mph? b. Data on the bird's position were recorded only intermittently. Explain how this means that the bird's actual average speed was higher than what you calculated in part a.

The bacterium Escherichia BIO coli (or E. coli) is a si nglecelled organism that lives in the gut of healthy humans and animals. Its body shape can be modeled as a 2-m-long cylinder with a I m diameter, and it has a mass of I x I0-12 g. Tts chromosome consists of a single double-stranded chain of DNA 700 times longer than its body length. The bacterium moves at a constant speed of 20 mis, though not always in the same direction. Answer the following questions about E. coli using SI units (unless speci fically requested otherwise) and co1Tect significant figures. a. What is its length? b. Diameter? c. Mass? d. What is the length of its DNA, in millimeters? e. If the organi sm were to move along a straight path, how many meters would it travel in one day?

The bacterium Escherichia BIO coli (or E. coli) is a singlecelled organism that lives in the gut of healthy humans and animals. When grown in a uniform medium rich in salts and amino acids, it swims along zig-zag paths at a constant speed changing direction at varying time intervals. Figure FIGURE P1 .61 P 1.61 shows the positions of an E. coli as it moves from point A to point J. Each segment of the motion can be identified by two letters, such as segment BC. During which segments, if any, does the bacterium have the same a. Displacement? b. Speed? c. Velocity?

The sun is 30 above the horizon. Tt makes a 52-m-long shadow of a tall tree. How high is the tree?

Weddell seals foraging in open water dive toward the ocean bottom by swimming forward in a straight-line path tipped below the horizontal. The tracking data for one seal showed it taking 4.0 min to descend 360 m below the surface while moving 920 m horizontally. a. What was the angle of the seal's path below the horizontal? b. What distance did the seal cover in making this dive? c. What was the seal's speed, in m/s?

A large passenger aircraft accelerates down the runway for a distance of3000 m before leaving the ground. It then climbs at a steady 3.0 angle. After the plane has traveled 3000 m along this new trajectory, (a) how high is it, and (b) how far horizontally is it, from its initial position?

Whale sharks swim forward while ascending or descendBIO ing. They swim a long a straight-l ine path at a sha llow a ngle as they move from the surface to deep water or from the depths to the surface. In one recorded dive, a shark started 50 m below the surface and swam at 0.85 mis along a path tipped at a 13 angle above the horizontal until reaching the surface. a. What was the horizontal distance between the shark's starting and ending positions? b. What was the total distance that the shark swam? c. How much time did this motion take?

Stalting from its nest, an eagle flies at constant speed for 3.0 min due east, then 4.0 min due nolth. From there the eagle flies directly to its nest at the same speed. How long is the eagle in the air?

John walks 1.00 km nolth, then turns right and walks 1.00 km east. His speed is 1.50 mis during the entire stroll. a. What is the magnitude of his displacement, from beginning to end? b. If Jane stalts at the same time and place as John, but walks in a straight line to the endpoint of John' s stroll, at what speed should she walk to atTive at the endpoint just when John does?

68. I What is the tree's speed of growth, in feet per year, from t = I yr to t = 3 yr? A. 12 ft/yr B. 9 ft/yr C. 6ftlyr D. 3 ft/yr

What is this speed in mis? A. 9 X 10-8 mis C. 5 X I0-6 mis B. 3 X 10- 9 mis D. 2 X 10-6 mis

At the end of year 3, a rope is tied to the very top of the tree to steady it. This rope is staked into the ground 15 feet away from the tree. What angle does the rope make with the ground? A. 63 B. 60 C. 30 D. 27