motion and forces Flashcards
what is newton’s first law
if there is no resultant force acting on an object it will :
Be at rest/stationary
move with constant speed
what is newton’s second law
a resultant force will cause an object to accelerate in the direction as the resultant force
What is the equation for velocity?
The equation for velocity (v) is
change in displacement
change in time
—————————
change in time
change in displacement
What equation describes acceleration?
Acceleration = initial speed minus final speed / time.
Define force.
Force is a push or pull acting upon an object as a result of its interaction with another object.
What is the equation for force?
The equation for force (F) is F=ma, where m is mass and
a is acceleration.
Explain the difference between balanced and unbalanced forces.
Balanced forces result in no change in an object’s motion, whereas unbalanced forces cause acceleration or changes in motion.
Explain Newton’s second law of motion and its equation.
Newton’s second law states that the force acting on an object is directly proportional to the rate of change of its momentum. Its equation is F=ma, where F is force, m is mass, and a is acceleration.
what is a scalar quantity
a quantity that has magnitude only
what is a vector quantity
a quantity that has both magnitude and direction
what is speed
speed is the distance travelled per time unit, for average speed use total distance (m/s)
what is the rate of change of speed
a measurement to show how quickly speed increases or decreases (m/s squared)
displacement
straight line distance in a particular direction (m)
velocity
the displacement per unit time (m/s)
What is acceleration
change in velocity/speed per unit time (m/s squared)
equation for constant speed
speed = total distance/total time
equation for average speed
A.S = total distance/total time
A.S = u+v/2
equation for rate of change of speed
rocos = initial speed - final speed / time
equation for velocity
velocity = displacement/time
equation for acceleration and deceleration
a = v-u / t
equation for gradient
rise/run
what does the gradient slope mean in a distance-time graph
speed
what does the horizontal line mean in a distance-time graph
stationary/at rest
what does the straight gradient sloop mean in a distance-time graph
constant speed
what does the gradient slope mean in a displacement-time graph
velocity
what does the straight positive gradient mean in a displacement-time graph
constant velocity forward
what does the straight negative gradient mean in a displacement-time graph
constant velocity backwards
what does the horizontal line mean in a displacement-time graph
stationary/ at rest
what does the gradient sloop mean in a speed-time graph
acceleration
what does the straight positive gradient mean in a speed-time graph
increasing speed
what does the straight negative gradient mean in a speed-time graph
decreasing speed
what does the area under the graph mean in a speed-time graph
distance
what time graphs allow negitive values
displacement and velocity
what does the straight positive gradient mean in a velocity-time graph
velocity increasing
what does the straight negative gradient mean in a velocity-time graph
velocity decreasing
what does the gradient sloop mean in a velocity-time graph
acceleration
what does the area under the graph mean in a velocity-time graph
displacement
definition of a moment of a forces
product of the force and the perpendicular distance between the force and the pivot
principle of a moment
for a beam to balance the total sum of the anticlockwise moment has to be equal to the total sum of the clockwise moment
equation for moment of a force
Moment of force = F x d
equation for principal of moments
cm = acm
F1XD1=F2XD2
definition for centre of gravity
the point through all the weight of an object appears to act
what makes an object stable
wide base
low centre of gravity
name me the forces acting on a car
friction
weight
reaction
thrust
name me the forces acting on a aeroplane
lift
weight
thrust
air resistance
name me the forces acting on a running dog and a human holding on to the dog leash
tension
weight
reaction
what is the definition of mass
the amount of matter in a body
what is the definition of weight
the force due to the pull of gravity on an object
equation for mass
mass = weight/ gravity
what is friction
a force with opposes motion
equation for newton’s second law
force = mass x acceleration
definition for Hooke’s law
the extension of the spring in directly proportional to the force applied, provided the limit of proportionality has not been exceeded
equation for hooke’s law
spring force = spring constant x spring stretch or compressed
f=kx
limit of proportionality
the point where a spring losses its elastic behaviour
