Friday

August 22, 2014

August 22, 2014

Posted by **sal** on Wednesday, October 19, 2011 at 11:38pm.

x = t2 + t

ft. At the same time, another car leaves the same intersection heading north, traveling

y = t2 + 3t ft

in t sec. Find the rate at which the distance between the two cars will be changing 3 sec later. (Round your answer to one decimal place.)

- calculus -
**Damon**, Thursday, October 20, 2011 at 4:49amx = t^2 + 1t which is 10 at t=3

y = t^2 + 3t which is 18 at t=3

dx/dt = 2 t + 1 which is 7 at t=3

dy/dt = 2 t + 3 which is 9 at t=3

r^2 = x^2 + y^2 = 434 at t = 3

so at t = 3, r = 20.6

2 r dr/dt = 2 x dx/dt + 2 y dy/dt

20.6 dr/dt = 10(7) + 18(9)

dr/dt = 11.3 ft/s

**Related Questions**

Calculus - A car leaves an intersection traveling west. Its position 5 sec later...

PHYSICS - a car traveling at a constant velocity of 30 m/sec passes an ...

PHYSICS - A car traveling at a constant velocity of 30.0 m/sec passes an ...

FREE BODY DIAGRAM calculus - A car is traveling north towards an intersection at...

Calculus - A team has been working to convert diesel-powered cars to run just as...

Algebraic - Salem and Vernon ville are 168 miles apart. A car leaves Salem ...

calculus - A team has been working to convert diesel-powered cars to run just as...

algebra - Car A leaves a certain point traveling at an average speed of 40 mph. ...

Physics - Momentum of cars at intersection - Car A(1750kg) traveling due south ...

Math story problem - Melissa and Emily leave by car from the same location ...