Arubber toy duck is at rest on an inclined plane. when the angle of inclination of the plane is increased to 36.0°, the toy duck begins to slide down the incline. then, when the angle is decreased to 29.0°, the speed of the toy duck is constant. what are the coefficients of static and kinetic friction between the toy duck and the incline?

As part of your daily workout, you lie on your back and push with your feet against a platform attached to two stiff springs arranged side by side so that they are parallel to each other. when you push the platform, you compress the springs. you do an amount of work of 79.0 j when you compress the springs a distance of 0.230 m from their uncompressed length. (a) what magnitude of force must you apply to hold the platform in this position? (b)how much additional work must you do to move the platform a distance 0.230 m farther? (c) what maximum force must you apply to move the platform a distance 0.230 m farther?