# Search results

1. ### Calculating centripetal force when radius is unknown

Heres the question "A ball with a mass of 250 g has a centripetal acceleration of 5 m/s2. What is the centripetal force acting on this ball? " Since radius depends on the string length I have no idea how to derive it from these 2 variables. The only formula I know for getting centripetal...
2. ### Vectors and Physics

Heres a diagram http://img19.imageshack.us/img19/6586/diagramqq.jpg [Broken] in that picture the boats traveling north from one side of the river to the other at 2m/s. This is the y component. The rivers current is dragging the boat West down river at 3m/s. x component. The overall...
3. ### Vectors and Physics

I'm only learning myself too but I think I can answer this. Your idea is correct. For example say the velocity vector is 15m/s 20degrees West of North. The car or whatever is traveling in that north of west direction at 15m/s. All velocity is is unit of displacement per unit of time so the x...
4. ### Spherical drop of oil question

Homework Statement A spherical drop of oil, 1 mm in diameter, falls on a water surface. The oil spreads out to cover a circular patch of diameter 60 cm. The oil spreads out until it forms a uniform layer on top of the water, only one molecule thick. What is the thickness of this layer...