Blocks E ( ) and F ( ) are in contact on a rough incline
PHYSICS · Multi-part · AP · Physics 1: Algebra-based · Force and Translational Dynamics · Force and Translational Dynamics
Problem
Blocks E (4.0kg) and F (6.0kg) are in contact on a 25∘ rough incline, with block F lower on the slope. The coefficient of static friction between each block and the incline is μs=0.30, and the coefficient of kinetic friction is μk=0.25. A force F directed parallel to the incline acts uphill on block F.
(a) For each block, write an expression for the forces acting parallel to the incline in terms of known symbols (m, g, θ, μ, etc.).
(b) Derive an expression for the minimum value of F required so that the two blocks move uphill together without one block sliding relative to the other.
(c) If F=120N and the blocks accelerate uphill, determine the magnitude of their acceleration and state the direction of kinetic-friction forces on each block during this motion.
(d) For the situation in part (c), calculate the magnitude of the normal contact force that block E exerts on block F.