Forces Flashcards
What’s the difference between torque and work?
Torque means that a force is applied perpendicular to the center or mass or pivot point
Work means a force is applied in the same direction (parallel)to the object
In what direction is torque positive? Negative?
Torque is positive in the counterclockwise direction and negative in the clockwise direction
What happens to angular motion in the cosine direction
The cosine of the force is equivalent to force in the parallel direction and therefore does not contribute to angular motion
How is potential energy converted when an object rolls? When it slides?
A rolling object will convert potential energy into rotational kinetic energy. This does not contribute to the speed of its movement i.e. angular velocity
How does the shape of an object contribute to its angular velocity?
The smaller an objects moment of inertia or how it’s mass in distributed around its center, the more its kinetic energy will contribute to its velocity.
Smaller moment of inertia =greater velocity
How Does Newton’s 1st law relate to velocity?
Newton’s 1st law states an object in motion will remain in motion until a force acts upon it.
Therefore an object already in motion at a constant velocity is experiencing 0 net force
How do you determine Normal Force on an incline?
F=mgcosø
How do you find the force of an object on an inclined planet?
F=mgsinø
Remember, acceleration of the object is gravity (g)*sinø
How do you find the coefficient of kinetic friction of an object on an incline?
Assuming the incline makes an angle ø with the ground and the object has a constant velocity/acceleration, then the coefficient of friction is equal to the tangent of ø
µFk=tanø
µFk=Force of friction/normal force
µFk=Ff/FN
Why is the coefficient of kinetic friction lower than the coefficient of static friction?
On a molecular level, the molecules of the two objects have more points of contact in static friction. When an object is already moving and has kinetic friction, there are fewer points of contact.
