Problem 4-12 - Vector components - Part 3 - (B)

A car is travelling along a winding highway at a constant speed of \(82\; km/h.\) At 3:00 p.m., the car is heading \(38.2^\circ\) east of north, and at 3:15 p.m. it is heading \(12.7^\circ\) south of east. Define the \(+x\) and \(+y\) directions to be east and north, respectively. Use Eq. 4-8 to determine the \(x\)- and \(y\)-components of the average acceleration during this time interval.  

Accumulated Solution

\(82\; km/hr = 22.8\; m/s \\ v_{fx} = 22.8 \cos 12.7^\circ = 22.24\; m/s\)

Vector coordinates v_i and v_f

Correct!

 

The \(y\) component of \(v_f\) is:

(A)    \(22.8 \sin 12.7^\circ = 5.01 \;m/s\)

(B)    \(22.8 \cos 12.7^\circ = 22.24\; m/s\)

(C)    \(-22.8 \sin 12.7^\circ = -5.01\; m/s\)

(D)   \(-22.8 \cos 12.7^\circ = -22.24\; m/s\)