P5:forces and motion

Question 1

whats a contact force

Answer 1

when objects physically touch

Question 2

whats a non contact force

Answer 2

when not touching

Question 3

whats a vector

Answer 3

a quantity that has magnitude and direction

Question 4

whats a scalar

Answer 4

quantity that only has magnitude

Question 5

whats a resultant force

Answer 5

overall force acting on a object

Question 6

give examples of scalars

Answer 6

distance, speed , mass, energy, temperature

Question 7

give examples of vectors

Answer 7

displacement, velocity, acceleration, force, momentum

Question 8

how is thinking distance affected

Answer 8

speed, distraction, alcohol, drugs and tiredness

Question 9

how is breaking distance affected

Answer 9

speed, condition of breaks, tires and roads, weather condition

Question 10

what does momentum(kgm/s) =

Answer 10

mass(kg) x velocity(m/s)

Question 11

what are all the EM emitted by

Answer 11

electrons

Question 12

how are EM waves produced

Answer 12

when electrons lose energy

Question 13

What does a higher frequency mean

Answer 13

more energy which means shorter wave lengths

Question 14

what does work done =

Answer 14

force x distance

Question 15

what does force = when it comes to elasticity

Answer 15

spring constant (n/m) x extension(m)

Question 16

what does acceleration =

Answer 16

change in velocity(m/s)/time

Question 17

what is suvat

Answer 17

s : displacement(m/s)
u : initial velocity
v : final velocity
a : acceleration(m/s^2)
t : time

Question 18

how do you calculate weight(n)

Answer 18

mass(kg) x gravitational field strength(n/kg)

Question 19

whats newtons first law of motion

Answer 19

when theres no resultantant force an objects motion is constant

Question 20

whats newtons 2nd law of motion

Answer 20

force(n) = mass(kg) x acceleration(m/s^2)

Question 21

what is the practical for acceleration

Answer 21

accelerate trolley with mass on string
use photogates to measure acceleration
change weight on string
draw a force - acceleration graph
straight line across origin which shows that f and a are directly proportional

Question 22

whats newtons 3rd law of motion

Answer 22

for every action there is an equal an opposite force

Question 23

in a closed system what happens to momentum before an event and after an event

Answer 23

total momentum before and event is equal to the total momentum after and event

Question 24

what happens in collisions

Answer 24

Momentum is conserved so the momentum of object increases
Which decreases the momentum of the other object
Mass of object is constant so velocity decreases

Question 25

Reasons why speed may change

Answer 25

Surface Tiredness Force

Question 26

What happens when a force moves through a fluid

Answer 26

Force drags on it It acts in the opposite direction of the object The greater the speed the greater the drag

Question 27

What happens to an object falling through a fluid

Answer 27

At the start weight is equal to resultant force Resultant force causes them to fall Air resistance is an upwards force that acts opposite to weight Air resistance is low at the start Resultant force decreases because of air resistance Air resistance increases as they collide with more particles Weight is constant so resultant force decreases and they are accelerating more Air resistance will increase to the same amount as the weight No resultant force So no resultant force Reach terminal velocity

Question 28

How does surface area affect air resistance

Answer 28

The larger the area which collisions can take place More air resistance Resultant force changes direction Slow down Resultant force decreases Until terminal velocity