forces, energy and power Flashcards
What should you always do before answering a forces question?
draw a free body diagram and label all the forces and their directions
How do you find friction?
F= Thrust-Friction
What are the effects of friction on a moving object?
slows an object down and loose energy
How do you find the horizontal component of a force?
Fh=Fcos(angle)
How do you find the vertical component of a force?
Fv=Fsin(angle)
What is component of weight parallel to slope?
=mgsin(angle) sin to climb
What is component of weight perpendicular to slope?
=mgcos(angle) cos across
How do you find the unbalanced force for a constant speed or stationary lift?
no unbalanced force
How do you find the unbalanced force for a lift accelerating and decelerating up?
Upwards- F=R-W
Downwards- F=W-R
How do you find the unbalanced force for a lift accelerating and decelerating down?
Upwards- F=W-R
Downwards- F=R-W
How do you find the unbalanced force for a lift in freefall?
Weight only
What is a force?
a push or pull measured in newtons
What is newtons first law?
An object will remain at rest , or continue with a steady speed in a straight line, unless acted upon by an unbalanced force
What does newtons second law mean?
An unbalanced force will cause a mass to have a change in its motion and can be expressed through f=ma
What is mass and weight?
Mass is the amount of stuff (or matter) in an object. It is measured in kilograms (kg).
Weight is a measure of the force pulling down on an object due to gravity. Weight is a force and is measured in newtons (N)
W=mg
