# Rotational bodies

• November 12th 2009, 01:24 PM
jddery
Rotational bodies
A car turns a corner with a radius of curvature of 18.2 m while braking to reduce its speed. If the brakes generate an angular deceleration of 0.7 rad/s2 what is the magnitude of the acceleration of the car half way through the corner when the car's linear speed is 4.2 m/s?

http://moodle.phys.ualberta.ca/file....n/car-bend.jpg
• November 12th 2009, 03:45 PM
skeeter
Quote:

Originally Posted by jddery
A car turns a corner with a radius of curvature of 18.2 m while braking to reduce its speed. If the brakes generate an angular deceleration of 0.7 rad/s2 what is the magnitude of the acceleration of the car half way through the corner when the car's linear speed is 4.2 m/s?

http://moodle.phys.ualberta.ca/file....n/car-bend.jpg

$|a| = \sqrt{a_T^2 + a_c^2}$

where tangential acceleration is $a_T = r\alpha$

and centripetal acceleration is $a_c = \frac{v^2}{r}$
• November 12th 2009, 05:23 PM
jddery
hey thanks that worked

now how did you come up with that equation? is that a defined equation in a text book?
or did you simply know that adding the tangential acceleration with the centripetal acceleration by means of Pythagorus would result in acceleration?
• November 12th 2009, 08:18 PM