Posted by Jacob on Tuesday, October 16, 2012 at 9:46pm.
A block is released from rest at the top of an incline which makes a 30 degree angle with the horizontal. The incline is 12 m long and it takes the block 25 seconds to reach the bottom. What is the coefficient of kinetic friction, between the block and the incline?

physics  Elena, Wednesday, October 17, 2012 at 4:43am
s=at²/2
a=2s/t²=2•12/25²=0.0384 m/s²
v=at=0.0384•25=0.96 m/s
PE=KE+W(fr)
PE=m•g•h=m•g•s•sinα,
KE=mv²/2,
W(fr) =μ•m•g•cosα•s,
m•g•s•sinα= mv²/2+ μ•m•g•cosα•s,
μ ={2g•s•sinα  v²}/2•g•cosα•s=
=tanα  v²/2•g•s •cosα
Answer This Question
Related Questions
 Physics  A block is released from rest at the top of an incline which makes a ...
 Physics  A block is released from rest at the top of an incline which makes a ...
 physics  A frictionless incline is 5.00 m long (the distance from the top of ...
 physics  A small block is released from rest at the top of a frictionless ...
 physics  A small block is released from rest at the top of a frictionless ...
 Physics  A block is released from rest at the top of an inclined plane. The ...
 Physics  A mass of 5.6 kg lies at the top of a frictionless incline. It is ...
 Physics  A mass of 5.6 kg lies at the top of a frictionless incline. It is ...
 Physics 1  A mass of 5.2 kg lies at the top of a frictionless incline. It is ...
 Physics 1  A mass of 5.2 kg lies at the top of a frictionless incline. It is ...
More Related Questions