A box is at rest on a slope with an angle ϴ. Find an expression for the static friction coefficient, μ, of the box.

Begin by drawing a diagram with all the vectors that act on the box. This should include the normal vector (N), the weight of the box (G), and the static friction force (Fs). Write down the equation for the static friction force (Fs = μN). Using Newton's Second Law of Motion, the forces acting on a static body will equal zero and thus the component of vector G that's parallel to the slanted plane, Gx, will equal Fs. Similarly the perpendicular G component, Gy, will be equal to N. To find Gx and Gy, a straight triangle is drawn connecting vector G and its components. The triangle is similar to that of the slope in the original diagram with the angle between Gy and G being ϴ. Inspecting the triangle we find that Gx = Gsin(ϴ) and Gy = G*cos(ϴ). by substituting everything into Fs , we receive: μ = sin(ϴ)/cos(ϴ) = tan(ϴ).

OL
Answered by Oliver L. Physics tutor

4066 Views

See similar Physics GCSE tutors

Related Physics GCSE answers

All answers ▸

Why would you get an electric shock if you touched a wire?


A ball of mass 1kg is rolled down a hill of height 10m. At the bottom it collides with another ball of mass 5kg. What speed does the second ball move away with? You can assume the collision between the balls is elastic.


How much work must be done on a 4.0kg frictionless trolley, to accelerate it from rest to a velocity of 5.0m/s?


Why would the National Grid limit the amount of fossil fuels we combust at peak times of energy demand?


We're here to help

contact us iconContact usWhatsapp logoMessage us on Whatsapptelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

© MyTutorWeb Ltd 2013–2025

Terms & Conditions|Privacy Policy
Cookie Preferences