Velocity, Acceleration, Displacement, Headache I have an exam tomorrow. Can you help me out with these physics questions? They are review questions that I am stuck on. 1) Distance is 45 km and it took 3 seconds what is the speed. If the displacement is 7 km north what is the velocity? *I know the speed is 15km/s, but I don't get the velocity. (I know velocity = displacement over time). 2) Draw a scale vector diagram to find the resultant displacement of the following scenario. A football is thrown 30 m north 85 degrees west. Then run 3 m north 10 degrees east. Finally kick 21 m east 80 degrees south. * I don't understand the degree part. 3) A cart is accelerating at a rate of 0.6m/s(squared). After 7 seconds it is moving at 4.7m/s(sq). What was it's initial velocity. *I got 32.9, is that correct? 4) A ball is rolling down a ramp from rest. How long will it take to reach a velocity of 6.0 m/s, if its acceleration is 1.5 m/s(sq)? * Really don't know where to start. Acceleration is velocity over time. So do I move it aaournd, so I have t=va? In which my answer should be 9? 5) Instantaneous velocity at 65 m/s? (From question 4) I'd like to know how to do each of these questions, as in my science teacher cared more about his baby than his own class (they had a baby).