Kinetics, the study of unbalanced forces causing motion, can be analyzed by three methods: inertia force or torque (dynamic equili
ium), work and energy, and impulse and momentum.
Consider the following as you complete your assignment:
For linear motion the inertia force is
· Equal to ma
· Acting through the center of gravity
· Opposite in direction to the acceleration
For rotational motion the inertia torque is
· Equal to C
· Opposite in direction to the angular acceleration
For a plane motion problem such as a rolling cylinder, try to
· Equate or relate linear acceleration to angular acceleration.
· Take moments at the rolling point of contact with the surface.
Questions
13–1.
Determine the acceleration of the 150-lb block in Figure P13–1 if the coefficient of kinetic friction is 0.4.
13–3.
A 130-kg cart is accelerated horizontally by a 250-N force pulling at an angle of 20° above horizontal. Neglecting rolling resistance, determine the acceleration of the cart.
13–7.
At what maximum acceleration rate can a 500-N test-strength cable lift a 40-kg mass?
13–8.
What force does a 180-lb man exert on the floor of an elevator that is moving downward and decelerating at 15 ft/s^2?
13–20.
The coefficient of kinetic friction for mass B in Figure P13–20 is 0.25. Determine the acceleration of mass A if it has a mass of (a) 30 kg and (b) 50 kg.
13–36.
A 1000-kW generator has a 3500-lb rotor that is accelerated from rest to 3600 rpm in 10 seconds. Determine the torque required. Assume the rotor to be a solid cylinder 40 in. in diameter.
13–41.
A 150-mm-diameter shaft with a mass of 20 kg is rotating at 900 rpm. A pulley mounted on the shaft has a mass moment of inertia of 0.15 kg â‹… m^2. If the shaft and the pulley coast to a stop due to a tangential frictional force of 8 lb at the outer radius of the shaft, determine the time required.