Question

You push a block of mass m up a plane inclined at angle θ
at constant velocity v with a force F parallel to the inclined plane. The coefficient of kinetic friction between the block and the plane is µk. Which is the correct equation for F? (g = gravitational acceleration)
A. F = mg
B. F = mg ( sin θ − µk cos θ ) C. F = mg ( sin θ + µk cos θ ) D. F = µkmg ( cos θ )

A car of mass m travels at constant speed v around a traffic circle of radius r. If the driver wanted to push the limits and drive around the traffic circle at twice the speed, determine the force F that would be necessary to keep the car traveling around the traffic circle at constant speed 2v?
A. F = 4mv^2/r r^
B. F = 2mv^2/r r^
C. F = -4mv^2/r r^
D. F = - 2mv^2/r r^

Answer 1

and what are your thoughts?