Acar is traveling down a straight stretch of highway at 90 kilometers per hour. the driver suddenly slams on the brakes and brings the car to a quick stop. as a result, the unbelted passengers will at first:
a. continues to move forward in a straight line.
b. come to a stop at the same time as the car.
c. be pushed against the door on the passenger side.
d. be pushed against the back of the seat.

Option A

Continues to move forward in a straight line

Explanation:

From the law of inertia, a body at rest or in motion motion at a constant speed maintains its state in a straight line unless acted upon by a force. In this case, all people in the car are moving at the speed of car of 90 km/h and when braking force is applied, the unbelted passengers will continue moving forward in a straight line. That's why it's advisable for all passengers in a car to fasten their safety belts.

see the picture for the vector

the magnitude of the vector by pythagorean theorem

r = √( (-10)^2 + (3)^2 ) = √109

magnitude = √109 units

the direction angle between vector and x-axis is

tan^(-1)(3/10) = 16.699

so the direction is approximately 16.7 degrees north of west