physics term 1

what happens when an object has balanced forces?

they are at equilibrium; they obtain their state of motion.

what happens when an object has unbalanced forces?

the object accelerates; their state of motion is disrupted.

what is the unit of force?

N (newtons).

what are the two types of forces?

contact and non-contact forces.

contact forces are...

when two objects are in contact, causing a force against each other.

friction is...

a contact force. it opposes motion in the opposite direction.

what is a "low coefficient of friction"?

two objects like ice, which defy friction by lessening it

air resistance is...

a contact force/friction. it is when an object is passing through a fluid.

what can air resistance also be called?

drag.

weight is...

a non-contact force. it is the force of gravity acting on an object.

how can you calculate weight?

weight = mass x acceleration of gravity

what is the different between weight and mass?

weight is the force of gravity acting on an object, measured in newtons. mass is the number of particles an object is comprised of, measured in grams.

how do you calculate the gravitational field of a point?

gravitational field strength = acceleration of freefall / mass

why would your weight change on the moon, but your mass would not?

the gravitational field strength of earth is stronger than on the moon, while your particles in the body will stay the same

how can we represent forces?

an arrow.

how does an object change direction?

a sideways force.

what is resultant force?

the difference between opposing forces. the force that acts on an object to disrupt its state of motion.

why do objects fall?

weight.

at all points near the earth, how is gravity?

equally strong.

when an object is falling, what does air resistance do?

combats the gravity and equalizes with the object

what is terminal velocity?

the fastest speed an object can travel as it goes through a fluid

in a circular motion, what is the force towards the middle?

centripetal force or the acceleration.

in a circular motion, what is the velocity forwards?

tangental velocity.

what are the factors which changes the effect of force?

the size of the force. the time of exerted force.

what is impulse?

the amount of force an object has in a period of time. the change of momentum.

what is the equation of impulse?

force multiplied by the time it is being exerted. final momentum subtracted by the initial momentum.

what is the unit of impulse?

N s (newton seconds).

what is momentum?

the amount of motion an object has. the velocity of the object multiplied by the mass of the object.

how can you calculate resultant forces with momentum?

change in momentum divided by the time of momentum.

what is collision?

the meeting of bodies as they exert force to each other.

what is the principle of conservation?

total momentum is constant, does not change because of an interaction between bodies.

what are vector triangles?

two forces which are perpendicular to eachother are connected by a line. sohcahtoa is used to calculate the angle. pythagoras theorem is used to calculate the force.

what are moments of force?

the tendency for an object to turn. the turning effect of an object.

what is the equation of moments?

force multiplied by the perpendicular distance.

how can you describe moments?

clockwise or anticlockwise.

what are moments also known as?

torque.

how can you increase a moment without changing the force exerted?

increase the length of the perpendicular distance.

what is the principle of moment?

if an object is at equilibrium, both the sum of anticlockwise and the sum of clockwise forces are equal to each other.