A car moving at a speed of 16 m/s accelerates at a rate of -4 m/s^2 to stop in time so it doesnt rear end another vehicle. How long does it take for the car to stop?

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

a=d/t

a="triangle"v/t

explanation:

a = acceleration