# Friction-less speed physics problem

1. Dec 16, 2004

### tthaitanium

a frictionless curve of radius 100 meters, banked at an angle of 45 degrees may be safely negotiated at a speed of?

2. Dec 16, 2004

### HallsofIvy

Staff Emeritus
FRICTIONLESS? Ouch! Calculate the accelaration vector of an object moving around the curve at speed "v". For what speed is this vector at 45 degrees to the vertical?

3. Dec 16, 2004

### tthaitanium

how would i do that?

4. Dec 16, 2004

### tthaitanium

also, theres another question i have..

the tiny planet mercury has a radius of 2400 kilometers and a mass of 2.2 x 10^23 kilograms. what would be the gravitational acceleration of an astronaut standing on the surface of mercury?

can someone help me take this step by step..i have no clue how to do this

5. Dec 19, 2004

### prasanna

Since the astrinaut is standing on the surface, the acceleration is zero!!!!

But if you meant the acceleration due to gravity,g, at the surface, there is a simple formula

started by truimphdog1 on 7 or 8 or 9 December (whichever date according to your time zone)

The formula required for this question is available there

try searching and tell me if you get it!

6. Dec 19, 2004

### \$id

The formula for the centripetal acceleration is v^2/R incase you didn't know