P2 Forces Revision Flashcards
Distance travelled =
speed x time
Balanced forces produce……
constant velocity
Unbalanced forces produce …..
acceleration in the direction of the force
Vector quantities
have size and direction
Scalar quantities
only have size
The gradient of a distance time graph tells you …
the velocity
The gradient of a velocity time graph tells you …
the acceleration
The unit of velocity is ….
m/s
The unit of force is ….
N
The area under a velocity time graph tells you ….
the distance travelled
Stopping distance =
Thinking distance + Braking distance
Thinking distance is affected by ….
things that affect the driver (tiredness, alcohol) and the speed of the vehicle
Braking distance is affected by ….
things that affect the car brakes or the road surface as well as the speed of the vehicle
Terminal velocity occurs when …….
Weight and Air Resistance forces are balanced
What happens to air resistance as speed increases?
Air resistance increases
Momentum depends on
mass and velocity (momentum = mass x velocity)
When an object is dropped …
gravitational potential energy turns into kinetic energy
When an object is lifted ……
kinetic energy turns into gravitational potential energy
Seat belts and air bags work by…..
increasing the time over which an object is brought to a halt, reducing the force needed.
Hooke’s law states that
force and extension are directly proportional
the gradient of a force extension graph ….
gives you the spring constant k
When the elastic limit of an object is exceeded …..
the object will not return to its original length
A mass of 70Kg on earth will have a weight of …
700N (70 x 10 = 700)
Mass = 3 Kg, Velocity = 10m/s, Momentum = ?
Momentum = m x v = 3 x 10 = 30Kgm/s
Mass = 3 Kg, Velocity = 10m/s, KE = ?
KE = 1/2 x 3 x 10 x 10 = 150J
Mass = 3Kg, Height = 20m, GPE = ?
GPE = 3 x 10 x 20 = 600J
Momentum is conserved means …….
total momentum after collision = total momentum before collision
Force = 30N, Distance moved = 6m, Work done = ?
Work done = F x d = 30 x 6 = 180J
