1.11-1.33 forces, movement, shape and momentum Flashcards
what is newtons first law?
an object will continue to move at the same speed in the same direction unless an external force acts upon it
what is newtons second law?
force = mass x acceleration
what is newtons third law?
for every action there is an equal and opposite reaction
what is a scalar quantity?
has size but no direction (speed, distance, mass)
what is a vector quantity
has size and direction (velocity, displacement, weight)
what is friction?
a force that opposes motion
how to calculate force
force = mass x acceleration
how to calculate weight
weight= mass x gravitational field strength
how to calculate stopping distance of a car
breaking distance + braking distance
what affects braking distance and what affects thinking distance?
breaking distance:
break qualities
road quality
weather conditions
thinking distance:
substance consumption (e.g alcohol)
age
what is hookes law?
The extension of a spring is directly proportional to the force applied, provided that the limit of proportionality is not exceeded
what is the difference between elastic and plastic deformation
elastic
-object returns to original shape after being stretched/squished (spring)
plastic
-object changes shape/breaks after being stretched/squished (plastic)
explain terminal velocity
-air resistance increases as speed increases
-eventually force becomes balanced meaning acceleration is 0 and therefore terminal velocity
how do you calculate moment?
moment = mass x velocity
how do you calculate force using moment
force = (final moment- initial moment) / time taken
