7 On the move Flashcards
What is displacement?
distance in a given direction
what is speed?
the change of distance per unit time
what is velocity?
the change of displacement per unit time (speed in a given direction)
what is the formula for speed?
v = s/t
what does a constant gradient mean in a distance time graph?
constant speed/velocity
how do you find the gradient with a distance time graph of changing speed?
draw a tangent at any point and calculate the gradient from that
what does constant velocity mean?
when an object moves at the same speed without changing direction
what is acceleration?
the change of velocity per unit time
what is uniform acceleration?
where the velocity of the object moving along a straight line changes at a constant rate
what is the formula for acceleration?
a = (v - u)/t
how can the formula for acceleration be rearranged?
v = u + at
what does the gradient of a velocity time graph equal?
the acceleration
what is equal to the displacement travelled on a velocity time graph?
the area under the graph
what can be used when there is constant acceleration?
suvat equations
what is acceleration of free fall?
acceleration of an object acted on only by the force of gravity
what is a projectile?
any object acted upon only by the force of gravity
what 3 principles apply to all projectiles?
- the acceleration of an object is always equal to g and downwards as gravity acts downwards. the acceleration therefore only affects the vertical motion of the object
- the horizontal velocity is always constant as the acceleration of the object doesn’t have a horizontal component
- the motion in the horizontal and vertical directions are independent of each other
what formula is used to work out horizontal displacement/velocity of a projectile?
s = vt
s - displacement
v - initial velocity
t - time
what is used to calculate the vertical component of velocity (or variables relating to the vertical velocity)?
suvat equations
what are the features of a drag force of a projectile?
- acts in opposite direction to direction of motion
- increases as speed increases
- has a horizontal component which reduces horizontal speed
- reduces maximum height of projectile if the initial direction is up
what is used to find the vertical and horizontal components of an initial velocity of a projectile?
trig
vertical - U sin x
horizontal - U cos x
U - initial velocity
x - angle with horizontal
