PHYSICS
posted by ALLISON .
The blade of a windshield wiper moves through an angle of 90.0° in 0.49 s. The tip of the blade moves on the arc of a circle that has a radius of 0.6 m.
What is the magnitude of the centripetal acceleration of the tip of the blade?

90 degrees of a circle is 1/4 the Circumference. Therefore it takes 0.49s to travel 1/4 of the way. Multiply .49 by 4 to receive the total amount of time it takes to make one revolution. To find velocity, find the circumference (2*r*pi). Divide the circumference by the time to get the velocity. The Centripetal Acceleration is (v^2/r).