Question

As a car accelerates from rest to highway speed, a pedestrian watching the motion sees positive...

As a car accelerates from rest to highway speed, a pedestrian watching the motion sees positive work done on the car because its kinetic energy increases. However, from the reference frame of someone driving in the same direction at highways speed, the car is initially moving (backward) and then becomes stationary, corresponding to negative work. Which observer is right?

Homework Answers

Know the answer?
Your Answer:

Post as a guest

Your Name:

What's your source?

Earn Coins

Coins can be redeemed for fabulous gifts.

Not the answer you're looking for?
Ask your own homework help question
Similar Questions
A car starts from rest and accelerates (at a constant rate) to a speed of 76.8...
A car starts from rest and accelerates (at a constant rate) to a speed of 76.8 km/h in 8.63 s. The car continues travelling at 76.8 km/h. What is the average speed of the car at 19.22 s, ie. over all the time it has been moving? Give your answer in km/h.
a) A car accelerates uniformly from rest and reaches a speed of 13.7 m/s in 10.9...
a) A car accelerates uniformly from rest and reaches a speed of 13.7 m/s in 10.9 s. The diameter of a tire is 71.8 cm. Find the number of revolutions the tire makes during this motion, assuming no slipping. Answer in units of rev. b) What is final rotational speed of a tire? Answer in units of rev/s.
A car accelerates uniformly from rest and reaches a speed of 21.0 m/s in 9.05 s....
A car accelerates uniformly from rest and reaches a speed of 21.0 m/s in 9.05 s. Assume the diameter of a tire is 59.0 cm. (a) Find the number of revolutions the tire makes during this motion, assuming that no slipping occurs. rev (b) What is the final angular speed of a tire in revolutions per second? rev/s
Car A starts from rest and accelerates in the x-direction at 4 m/s^2 at the precise...
Car A starts from rest and accelerates in the x-direction at 4 m/s^2 at the precise moment that it is passed by Car B traveling in the same direction at a constant speed of 40 m/s. (Draw a free-body diagram).                       a) How long does it take Car A to catch Car B?                       b) How far has Car A traveled when it catches Car B?                       c) How fast is Car A traveling when it catches Car B?                      ...
10.4-5-6) A) A car traveling on a flat (unbanked), circular track accelerates uniformly from rest with...
10.4-5-6) A) A car traveling on a flat (unbanked), circular track accelerates uniformly from rest with a tangential acceleration of 2.10 m/s2. The car makes it one quarter of the way around the circle before it skids off the track. From these data, determine the coefficient of static friction between the car and track. ________ (Hint: You are not given a value of the radius of the track. Think through the problem using the symbol R for this value and...
A jet accelerates at a=3.92 m/s^2 from rest until it reaches its takeoff velocity of 360...
A jet accelerates at a=3.92 m/s^2 from rest until it reaches its takeoff velocity of 360 km/hr. It has to travel for 5 seconds at its takeoff velocity before taking off. What's the minimum distance that the jet will travel on the runway? A car backs up at a constant speed for a short time, then applies the brakes and steadily comes to rest. Sketch velocity-time and position-time graphs that depict the car's motion. Assume that the forward direction is...
Two boxes are stacked, with box B placed on top of box A. If box A...
Two boxes are stacked, with box B placed on top of box A. If box A is pushed such that both boxes move with a decreasing speed, is there any friction on either box? (a) Kinetic friction on box A and no friction on box B (b) Kinetic friction on box A and static friction on box B (c) Kinetic friction on box A and kinetic friction on box B (d) Static friction on box A and kinetic friction on...
8 through 10 done please!! 3.13.6 Question 110 pts A 319 kg motorcycle is parked in...
8 through 10 done please!! 3.13.6 Question 110 pts A 319 kg motorcycle is parked in a parking garage. If the car has 35,494 J of potential energy, how many meters above ground is the car? Report your answer to 1 decimal place. Please do not include units or the answer will be marked incorrect. Flag this Question Question 210 pts A box sitting on the top of a hill has 252 J of potential energy. If the hill is...
just do questions 5 through 10 3.13.6 Question 110 pts A 319 kg motorcycle is parked...
just do questions 5 through 10 3.13.6 Question 110 pts A 319 kg motorcycle is parked in a parking garage. If the car has 35,494 J of potential energy, how many meters above ground is the car? Report your answer to 1 decimal place. Please do not include units or the answer will be marked incorrect. Flag this Question Question 210 pts A box sitting on the top of a hill has 252 J of potential energy. If the hill...
answer all questions 3.13.6 Question 110 pts A 319 kg motorcycle is parked in a parking...
answer all questions 3.13.6 Question 110 pts A 319 kg motorcycle is parked in a parking garage. If the car has 35,494 J of potential energy, how many meters above ground is the car? Report your answer to 1 decimal place. Please do not include units or the answer will be marked incorrect. Flag this Question Question 210 pts A box sitting on the top of a hill has 252 J of potential energy. If the hill is 279 meters...