2-forces and motions Flashcards by nour waleed

whats the distance time graph for a stationary object

horizontal line

How well did you know this?

Not at all

Perfectly

whats the distance time graph for an object at constant speed

straight line with a positive slope

How well did you know this?

Not at all

Perfectly

what does the distance time graph gradient represent

speed

How well did you know this?

Not at all

Perfectly

whats the formula for speec

speed = distance traveled/time taken

How well did you know this?

Not at all

Perfectly

what typa quantity is speed

a scalar quantity,magnitude but no direction

How well did you know this?

Not at all

Perfectly

what type od quantity is distance

scaler

How well did you know this?

Not at all

Perfectly

what is displacement

ditance in a given direction. its a vector quantity

How well did you know this?

Not at all

Perfectly

what is velocity

speed in a given direction

How well did you know this?

Not at all

Perfectly

why is velocity a vector quantity

because it has both a magnitude and direction

How well did you know this?

Not at all

Perfectly

whats the formula for velocity

velocity=displacement/time

How well did you know this?

Not at all

Perfectly

whats tehe formula for acceleration

change in velocity/time

How well did you know this?

Not at all

Perfectly

how can u find distance from a velocity time graph

the area under a velocity time graph

How well did you know this?

Not at all

Perfectly

what does it mean of the velocity time graph has a horizontal gradient

constant acceleration

How well did you know this?

Not at all

Perfectly

what happens if 2 objects push eachother apart

if they have diff mass they will move with diff speeds
if they have the same mass there will be equal and opposite momentum

How well did you know this?

Not at all

Perfectly

what is meant by deceleration

negative acceleration

How well did you know this?

Not at all

Perfectly

what is the formula for momentum

mass x velocity

How well did you know this?

Not at all

Perfectly

whats the unit for momentum

kg/m/s

How well did you know this?

Not at all

Perfectly

what happens if resultant force exerted on an object increases

total acceleration increases

How well did you know this?

Not at all

Perfectly

what is newtons second law

force(n) is equal to mass (g) times acceleration

how do you find the gradient by drawing a tangent on a graph

height/base

descrube newtons 2nd law

f=ma so objects acceleration is the same direction as the resultant force on the object, force must be accting on object to cause or change an acceleration.

why is driving velocity constant

driving force is equal to resistant force (ex friction or air)

what is stopping distance and what is it made of

shortest diistance taken for a vehicle to stop
thinking distance(distance traveled during drivers reaction time) + breaking distance(distance traveled by car during breaking)

whatre the factors that effect thinking distance

tiredness alcohok and drugs since driver may be distracted

whatre the factors effecting stopping distance

higher speed,bad weather conditions and bad car maintenence will all lead to a longer stopping distance (car takes longer to stop)

what happens when car decelerates

breaks overheat due to friction between breaks and wheels then kinetic energy os transfered into thermal energy

whats newtons 1st law

if resultant force acting on a object is 0 -a moving object will continue to move at the same velocity -a stationary object will remain at rest.

what is newtons 3rd law

Whenever two objects interact, the forces they exert on each other are equal in magnitude and opposite in direction.

what is resultant force

total force acting on an object. a single force that has the same effect on the motion as all the original forces acting together.

what happens in terms of acceleration if the resultant force on an object is not zero

the object will accelerate in the direction of the resultant force.

what is conservation of momentum

in a closed system the total momentum before an interaction is equal to the total momentum after the interaction.

whats the relationship between force, F, change in momentum, ∆p, and time, t,

force = change in momentum/time

what happens to objects moving fast through fluids

object experiences friction. The faster the object moves, the greater the frictional forces (drag) acting on it.

what happens to objects moving throught fluid in terms of acceleration

- initially accelerate due to the force of gravity -> the drag forces increase as the velocity increases. -> the resultant force will be zero and the object will move at its terminal velocity.

why are parachutes designed (in terms of terminal velocity)

to increase the drag force on a parachutist so that the terminal velocity is reduced.

what does streamlinig do

reduces the drag force on an object so that its maximum velocity is increased.

whats the center of mass

is the point at which the mass of the object may be thought to be concentrated.

how do you calculate moment

force times perpendicular distance

whats the unir of moment

newton meters (Nm)

where is the center of mass in a suspended object

directly beneath the point of suspension

where is the center of mass in a symmetrical object

along the axis of symmetry

whats the moment of a force

measure of turning effect on the force of an object

what happens if an object is balanced

the total clockwise moment must be exactly balanced by the total anticlockwise moment about any pivot.

what happens if the line of action (center of mass) lies outside base of an object

there will be a resultant moment and the body will topple.

how can stability of an object be increased

lowering the center of mass and increasing its base distance

when do objects topple

if its point of turning isnt 0 and its line of action acts AWAY from the equilibrium (balanced base)

how can simple levers be used

force transmitters, they transfer force from 1 side of pivot to another