Question

In: Physics

A bicyclist rides on a North-South trail from her home to work. She starts at home...

A bicyclist rides on a North-South trail from her home to work. She starts at home and rides due North for 22 minutes with a velocity of 7.2 m/s. She gets tired, so she slows down and rides for 36 minutes due North with a velocity of 5.1 m/s. Suddenly, she realizes that she missed her destination, frantically turns around, and rides due South for 8.0 minutes with a velocity of 10.1 m/s before reaching work.

a. What is her average velocity (magnitude and direction) between her home and work?

b. What is her average speed between her home and work?

c. Sketch a position (m) versus time (s) graph of her trip from her home to work. Consider her home to be the origin. Be sure to label both axes and scale them appropriately.

Solutions

Expert Solution

let

t1 = 22 minutes, v1 = 7.2 m/s
t2 = 36 min, v2 = 5.1 m/s
t3 = 8 min, v3 = 10.1 m/s

a)
average velocity = total displacement/time taken

= (v1*t1 + v2*t2 - v3*t3)/(t1+t2+t3)

= (7.2*22 + 5.1*36 - 10.1*8)/(22 + 36 + 8)

= 3.96 m/s (towards north)

b) average speed = total distance travelled/time taken

= (v1*t1 + v2*t2 + v3*t3)/(t1+t2+t3)

= (7.2*22 + 5.1*36 + 10.1*8)/(22 + 36 + 8)

= 6.41 m/s

c)


Related Solutions

In a park: a 75 kg bicyclist rides 5.8 m/s north; a 24 kg dog runs...
In a park: a 75 kg bicyclist rides 5.8 m/s north; a 24 kg dog runs 3 m/s east chasing a 3.3 kg squirrel running 2.6 m/s the same way; 200 kg park bench remains stationary; and a 43 kg child runs 1 m/s 45◦ south of east. What is the magnitude of the total momenta of this park system? Report the value in kg*m/s rounded to the nearest whole number.
A bicyclist starts from rest and accelerates to 5 m/s in 20 s. The wheels of...
A bicyclist starts from rest and accelerates to 5 m/s in 20 s. The wheels of the bicycle have a diameter of 80 cm. a) What is the angular velocity of the wheels at maximum speed? b) What is the angular acceleration of the bicycle wheels during this time? c) Find the number of revolutions the wheels make during this time. d) Find the average angular velocity of the wheels between the start and finish.
Moana is a sailing from her home to a nearby island which is 215 miles north...
Moana is a sailing from her home to a nearby island which is 215 miles north and 33 miles west. There is a constant ocean current of 0.50 knots moving from west to east. Moana can sail her boat at a cruising speed of 5.5 miles per hour in still water. 1. What angle should Moana sail to get to the island? 2. How long will it take her to get there? 3. Moana’s friend Maui is floating on a...
Shelli graduates from the University of South next month on her 25th birthday, and she is...
Shelli graduates from the University of South next month on her 25th birthday, and she is excited to begin her new career. Because she wants to have a comfortable living when she retires, Shelli has decided to begin planning for her retirement now. As a result, she is currently evaluating the amount she needs to contribute to a retirement fund satisfy her financial requirements at retirement. After speaking to retired friends and relatives, Shelli estimates she will need $60,000 each...
The "Trail of Tears", which removed the Cherokee and Seminoles from the American South, is fairly...
The "Trail of Tears", which removed the Cherokee and Seminoles from the American South, is fairly common knowledge; but Black Hawk's War and subsequent removal, at the same general time and by the same President, is invariably ignored. Determine why Black Hawk is overlooked and post this explanation by the end of Wednesday. Be sure to include at least two historical examples in support of your explanation..  
Anna Laura rides her bike. First she travels 3.5 km due east, then she takes a...
Anna Laura rides her bike. First she travels 3.5 km due east, then she takes a left turn and travels 2.5 km due north. Draw a graph illustrating the motion; be sure to choose a valid coordinate system and indicate the length scale of your axes. Draw the displacement vector x. Write the vector x include the magnitude and the direction; the direction can be an angle relative to one of your axes.
Amira sells auto parts from her home. She usually sells the parts to her neighbors and...
Amira sells auto parts from her home. She usually sells the parts to her neighbors and friends. She has been doing this for a long time. Emma owns a factory that makes auto parts. Emma has sold auto parts to Amira each year for the past ten years. Both Emma and Amira try to do what everyone else in the auto parts business does, which is selling the parts and then installing them. One day, Amira decides that she wants...
Elaine is an accountant for Randolph Corporation. She telecommutes and works mainly from her home in...
Elaine is an accountant for Randolph Corporation. She telecommutes and works mainly from her home in Cleveland, Tennessee. Twice a month she travels to Alpharetta, GA meetings at the corporate office. In which state’s payroll factor should Elaine’s compensation be included if: a) Elaine is an employee and is covered by the qualified retirement plan of her Georgia-based employer? b) Elaine works as an independent contractor for several clients, including the Georgia-based firm? c) Elaine is an employee, and for...
Jamie has been accepted to a university in a city far from her home. She will...
Jamie has been accepted to a university in a city far from her home. She will need to rent an apartment and has two choices. The first choice , cost $1,000 per month, and is within walking distance of the university. The second apartment costs $925 per month, but Jamie will have to buy a bus pass in order to get to the university. The pass costs $100 per month. Jamie has been hired to work part time at a...
Annie starts to save for her retirement right after she gets her first job at age...
Annie starts to save for her retirement right after she gets her first job at age 22. For twenty years, she puts $8,000 a year in her 401k and earns 10% for her investment. When she is 42, she stops making contribution but does not make any withdrawal until she retires at 65. How much would she have when she retired? Annie’s sister, Amy, started her 401k when she is 40 years old and she wants to have the same...
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT