Arunner sprints around a circular track of radius 120 m at a constant speed of 7 m/s. the runner's friend is standing at a distance 240 m from the center of the track. how fast is the distance between the friends changing when the distance between them is 240 m? (round your answer to two decimal places.)
Solved
Show answers
More tips
- F Food and Cooking Deflope: What is it and how does it work?...
- P Philosophy Personal attitude towards Confession: how to prepare and undergo the procedure correctly?...
- H Health and Medicine Flu: How to Recognize It by the First Symptoms?...
- F Food and Cooking How to Sober Up Quickly? Important Facts and Tips...
- H Health and Medicine How to Properly Take a Blood Sugar Test?...
- H Health and Medicine Simple and Effective: How to Get Rid of Cracked Heels...
- O Other How to Choose the Best Answer to Your Question on The Grand Question ?...
- L Leisure and Entertainment History of International Women s Day: When Did the Celebration of March 8th Begin?...
- S Style and Beauty Intimate Haircut: The Reasons, Popularity, and Risks...
- A Art and Culture When Will Eurovision 2011 Take Place?...
Answers on questions: Physics
- P Physics Brandon buys a new seedoo he goes 12km north from the beach he jumps wakes for 6km to the east...
- P Physics If it takes Jeff 3 hours and 33 minutes to drive 500 miles, what is his average velocity over this time?...
- P Physics ANSWER QUICK PLS!! (04.02 MC) Pam observed many small earthworms in the backyard of her house after a heavy rain. What most likely formed the earthworms? Select one: a....
- P Physics An instrument with a longer tube or larger body has a natural frequency...
- P Physics Convergent faults can form mountains and volcanoes. happen when tectonic plates move away from one another. create new oceanic crust through sea-floor spreading. happen...
- P Physics 7. A musician is staying near the motorway and is playing a constant 300 Hz tone on his flute. You are driving along the motorway at 100 km/h. What is the frequency you...
- P Physics The kinetic energy of an object is quadrupled. its momentum will change by what factor?...
- H History K- match the line from the preamble with the picture to which it is referring...
- B Biology What degrees is the tilt of the earth...
- H History 9. what happened at the party convention for the democrats that affected the 1860 presidential election? a the democrats nominated jefferson davis for president. o b the...
Ответ:
6.78 m/s
Explanation:
Let the distance between the two friends is x .
Radius, r = 120 m
v = 7 m/s
Angular velocity, ω = v / r = 7 / 120 rad/s
Use the law of cosines for the triangle OAB
x^2 = 120^2 + 240^2 - 2 x 120 x 240 x Cosθ ...... (1)
differentiate with respect to t on both the sides
2 x dx/dt = - 57600 x (-Sinθ) dθ/dt
Put x = 240 m in equation (1), we get
240^2 = 120^2 + 24062 - 57600 Cosθ
Cosθ = 1/4
So, by the use of right angled triangle, Sinθ = √15/4
Put all the values in equation (2), we get
Ответ: