Wednesday

November 26, 2014

November 26, 2014

Posted by **Mr. goodstuff** on Tuesday, January 17, 2012 at 11:53am.

- calculus -
**Reiny**, Tuesday, January 17, 2012 at 1:39pmmake a sketch

At a time of t hrs,

let the distance the police car is from the intersection be x miles

let the distance the speeding car is from the intersection be y miles

let the distance between them be d miles

d^2 = x^2 + y^2

2d dd/dt = 2x dx/dt + 2y dy/dt

d dd/dt = x dx/dt + y dy/dt

given: x = .6, y = .8 , dx/dt = -60 , dd/dt = 20

( I made dx/dt negative because the value of x is decreasing)

d^2 = .6^2 + .8^2 = 1

d = 1

1(20) = .6(-60) + .8dy/dt

20 + 36 = .8 dy/dt

dy/dt = 56/.8 = 70

The car was speeding at 70 mph

**Answer this Question**

**Related Questions**

Calculus AB - A police car is chasing a suspect. The policemen is at point y=0.6...

calculus - A police car is driving northward, chasing a vehicle which has just ...

Physics - A car is speeding at 33.4 m/s. A police car starts in pursuit from ...

CALCULUS - A gas station stands at the intersection of a north-south road and an...

Calculus - 4. A gas station stands at the intersection of a north-south road and...

Physics - A police car is traveling east at 40.0 m/s along a straight road, ...

physics - Two cars are approaching a perpendicular intersection without a stop ...

physics - A speeding car is pulling away from a police car. The police car is ...

calculus - A police cruiser hunting for a suspect pulls over and stops at a ...

physical - You are driving along a highway at 27.7 m/s when you hear a siren. ...