Posted by **sarah** on Friday, November 2, 2012 at 7:53am.

a drunken motorist who is moving at a constant velocity of 90 km/h passes a stationary police patrol car. The patrol car immediately gives chase at a constant acceleration and catches up with the motorist after a distance of 10 km. Calculate the time taken by the patrol car to catch up with the motorist.

- physics -
**drwls**, Friday, November 2, 2012 at 8:48am
Start counting time t from when the drunk motorist passes. Let his distance travelled be X1 and the distance travelled by the police car be X2.

X1 = V*t

X2 = (a/2) t^2

X1 = X2 when both equal 10 km. That is when the police car catches up.

t = 10 km/(90 km/h) = 1/9 h = 6.67 minutes

You could also solve for the police car's acceleration a, but they don't ask for that.

## Answer This Question

## Related Questions

- physics - A speeder traveling at a constant speed of 125km/h races past a ...
- Physics - A speeder traveling at a constant speed of 102 km/h races past a ...
- Physics - A speeding motorists passes a stopped police car. At the moment he ...
- Physics - A speeding motorcyclist is traveling at a constant speed of 31.1 m/s ...
- Math - A motorist traveling 55 mph is being pursued by a highway patrol car ...
- physics - A speeder doing 50.0 mi/hr (about 22 m/s) in a 25 mi/hr zone ...
- Physics - A motorist traveling at 30 m/s passes a parked police car. At the ...
- physics(kinematics) - A police officer in a patrol car parked in a 70 Km/h speed...
- physics - police officer in a patrol car parked in a 70km/h zone observe a ...
- physics - A student driving at a constant speed of 45 m/sec passes a highway ...

More Related Questions