Please answer this question in full Suppose you are driving a car in a countercl
ID: 1399072 • Letter: P
Question
Please answer this question in full
Suppose you are driving a car in a counterclockwise direction on a circular road whose radius is r = 350 m (see the figure). You look at the speedometer and it reads a steady 30.7 m/s. (a) What is the angular speed of the car? (b) Determine the acceleration (magnitude and direction) of the car. (c) To avoid a rear-end collision with the vehicle ahead, you apply the brakes and reduce your angular speed to 4.82 x 10^-2 rad/s in a time of 4.05 s. What is the tangential acceleration (magnitude and direction) of the car?Explanation / Answer
here,
radius of the circular road , r = 350 m
tangential speed of car , v = 30.7 m/s
(a)
angular speed of car , w = v/r
w = 30.7/350
w = 0.0877 rad/s
angular speed of car is 0.0877 rad/s
(b)
accelration of the car towards the centre be a
a = v^2/r
a = 30.7^2/350
a = 2.69 m/s^2
accelration of the car towards the centre is 2.69 m/s^2
(c)
time for reducing , t = 4.05 s
w1 = 0.0482 rad/s
let the final velocity be v1
v1 = r*w1
v1 = 350 * 0.0482
v1 = 16.87 m/s^2
using first equation of motion
v = u + a * t
16.87 = 30.7 + a * 4.05
a = - 3.41 m/s^2
the tangential accelration , at = 3.41/r
at = 3.41 / 350
at = 9.76*10^-3 rad/s^2
the tangential accelration is 9.76*10^-3 rad/s^2 and direction is opposite to the car motion