A speeding truck slams on the brakes and accelerates at -7.30 m/s^2. How fast was the truck going before it slammed on the brakes?

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

the answer to this is proletariats.

hope this : )