(adsbygoogle = window.adsbygoogle || []).push({}); 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).

**Physics Forums | Science Articles, Homework Help, Discussion**

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Homework Help: SO I have an Exam Tomorrow. Review Questions!

**Physics Forums | Science Articles, Homework Help, Discussion**