Forces Flashcards
What is the net force?
Associated with the resultant force, sum of all forces acting on a body
resultant- result of all the forces acting on a body
What happens when the net force is 0?
Forces are balanced; the horizontal forces and the vertical forces are the same
the performer will be at constant velocity or stationary
What happens when the net force isn’t 0?
The performer is unbalanced and is either decelerating or accelerating or moving through the air
What is the weight equation?
mass x acceleration
What is friction?
Force opposes the motion of two surfaces in contact
What are the basic factors that affect friction?
The roughness/smoothness of the contact surface
the contact surface
temperature- a increase in temperature increases friction and increases speed
an increase in mass increases friction, gravity pulls down
What is air resistance?
The force opposing an object moving through the air
What are some of the basic factors that affect air rreisatnce?
Velocity, am increase in velocity increases air resiatnce
the smoothness of the surface, air will carry over quicker if smooth
the shape of an object, streamlined
cross sectional area, an increase in area means greater air resistance
How would a sprinter starting attribute to an ubalanced forces?
The performer will be stationary on the blocks so all forces are balanced and a net force of 0
tp accelerate the performer must initiate a greater reaction force
air resistance will be smaller than the friction force as lower to the ground so performer can accelerate makes the sprinter uxnabalcned
During the sprinting race how does a performer maintain balanced froces>
At a constant velocity so all forces are balanced net force is 0
At the end of a sprinting race how will the forces be unbalanced?
The air resistance force will be greater than the friction force as performer is slowing down and taking foot off gas thus decelerating and creating no net force of 0
arms are out and upright so greater exposure to air resistance
How is a high jumper an example of an uneven vertical forces?
Needs to have a greater reaction force to the weight force to generate unbalanced motion to get off ground otherwise will remain on ground. The performer will apply a greater reaction through foot or muscle to accelerate in air and producing a net force of not 0
During the high jumper going over the bar what forces will be present and how?
The high jumper will have no reaction force as no contact with the ground so weight will be more and will accelerate quicker
Exam tips of
Weight always through centre of mass
air reisatcne always through centre of mass
reaction force alway through limb touching ground
