promotion image of download ymail app
Promoted

A block starts at rest and slides down a 3 meter long incline plane at 30 degrees in 3 seconds.?

A block starts at rest and slides down a 3 meter long incline plane at 30 degrees in 3 seconds. Calculate the coefficient of kinetic friction between the block and the incline plane. Hint: use kinematics to find the acceleration, then use a force diagram to solve for the coefficient of kinetic friction.

2 Answers

Relevance
  • 2 months ago

    find a

    d = Vi t + 1/2 a t^2

    you have t and d and Vi=0

    solve for a

    then

    Fnet =  m a

    let's take m as 1 kg for convenience

    and 

    Fnet = Fp - Ff = m g sin(angle) - Ff

    solve for Ff

    then

    mu = Ff/Fn = Ff / (m g cos(angle) )

    I get about 0.5

    When you get a good response,

    please consider giving a best answer.

    This is the only reward we get.

    • Commenter avatarLogin to reply the answers
  • Anonymous
    2 months ago

    distance = 1/2 * a * time^2

    3 m = 1/2 * a * (3 sec)^2, a = 2/3 m/sec^2

     

    if there was no friction, the acceleration of the block would be g * sin 30 = 4.905 m/sec^2 so there is a lot of friction.  

     

    Force of gravity acting on the block = m * g * sin 30

    Force of friction acting on the block in the opposite direction = m * (4.905 m/sec^2 - 2/3 m/sec^2)

     

    Kinetic coefficient of friction = m * (4.905 m/sec^2 - 2/3 m/sec^2) / m * g * sin 30 = 0.865

    • Commenter avatarLogin to reply the answers
Still have questions? Get your answers by asking now.