Forces and Motion. Force. FORCE is a push or a pull applied to an object that will cause it to start moving, stop moving or change its speed or direction Demonstration. Force. Force = Mass x Acceleration F = MA Force is measured in Newtons (N) which is one kilogram meter per second squared
or kilograms (kg)
Scales pushing up
Weight downSUPPORT FORCE
Driving at constant velocity
Force from road
Terminal velocity in parachuting
Ffriction = µFnormal
µ = the coefficient of sliding friction (has no units)
product of the friction b/w materials and amount of force
1. Ben is walking through the school cafeteria but does not realize that the person in front of him has just spilled his glass of chocolate milk. As Ben, who weighs 420 N, steps in the milk, the coefficient of sliding friction between Ben and the floor is suddenly reduced to 0.040. What is the sliding force of friction between Ben and the slippery floor?
3. A rightward force is applied to a 10-kg object to move it across a rough surface at constant velocity. The coefficient of friction, µ, between the object and the surface is 0.2. Use the diagram to determine the gravitational force, normal force, applied force, frictional force, and net force.
(Neglect air resistance.)
Vertical Displacement (y)
½ gt2Horizontally Launched Projectile(initial speed (vx) = 25 m//s)
= 1.6N / 2.2kg
2. An applied force of 50 N is used to accelerate an object to the right across a frictional surface. The object encounters 10 N of friction. Use the diagram to determine the normal force, the net force, the mass, and the acceleration of the object. (Neglect air resistance.)
3. Rose is sledding down an ice-covered hill inclined at an angle of 15.0° with the horizontal. If Rose and the sled have a combined mass of 54.0 kg, what is the force pulling them down the hill?