The moment due to friction for a steel pipe pressed against an icy surface with a given load force and coefficient of friction is 0.0661 N-m. This is calculated by multiplying the force of friction by the pipe's effective radius where friction occurs.
Step-by-step explanation:
The question involves calculating the expected magnitude of the moment due to friction exerted by a steel pipe on an icy surface. Moment of friction, also known as torque, is determined by the equation τ = F•r, where F is the force of friction, and r is the radius of the pipe where friction occurs. The force of friction (F) can be calculated using the coefficient of friction (μ) and the normal force (N), given by F = μ•N. In this case, the normal force is the load force of 118 Newtons, and the coefficient of kinetic friction is 0.02. The radius (r) of the pipe where friction occurs is the outer radius minus the wall thickness, which is 3 cm - 2 mm = 2.8 cm. To find the moment due to friction, we must convert the radius to meters by dividing by 100, then use the equation τ = (μ•N)•r to find the torque.
Let's calculate it:
Force of friction (F) = μ•N = 0.02 • 118 N = 2.36 N
Radius (r) in meters = 2.8 cm / 100 = 0.028 m
Moment due to friction (τ) = F•r = 2.36 N • 0.028 m
Therefore, the moment of friction is τ = 2.36 N • 0.028 m = 0.06608 N-m. When rounded to four decimal places, the expected magnitude of the moment due to friction is 0.0661 N-m.