Posted by **john** on Saturday, December 13, 2008 at 10:16pm.

A student wants to determine the coefficients of static friction and kinetic friction between a box and a plank. She places the box on the plank and gradually raises one end of the plank. When the angle of inclination with the horizontal reaches 30°, the box starts to slip, and it slides 2.4 m down the plank in 3.6 s at constant acceleration.

(a) What is the coefficient of static friction?

(b) What is the coefficient of kinetic friction?

- PHYSICS -
**drwls**, Saturday, December 13, 2008 at 10:21pm
a) tan 30

b) write the equation of motion, with a retarding force proportional to the kinetic friction coefficient, Uk. Compute the acceleration from the fact it takes 3.6 s to make it down the plank, starting at zero velocity. Solve for Uk

- PHYSICS -
**john**, Sunday, December 14, 2008 at 3:15pm
During an Olympic bobsled run, the Jamaican team makes a turn of radius 7.6 m at a speed of 97.2 km/h. What is their accelaration in g?

## Answer This Question

## Related Questions

- physics - A student wants to determine the coefficients of static friction and ...
- Physics - A student wants to determine the coefficients of static friction and ...
- physics - a student wants to determine the coefficient of static friction and ...
- Physics - 1. A box is placed on the end of a 3 meter plank. One end of the plank...
- physics - A 2.0kg box rests on a plank that is inclined at an angle of 65° above...
- physics - A 5-kg crate is resting on a horizontal plank. The coeï¬ƒ- cient of ...
- physics - a 5-kg crate is resting on a horizontal plank. the coefficient of ...
- spring- physics - A 2.0-kg box rests on a plank that is inclined at an angle of ...
- Spring Physics - A 2.0 kg box rests on a plank that is inclined at an angle of ...
- Simmons - A 2.0 kg box rests on a plank that is inclined at an angle of 65° ...

More Related Questions