force and motion

Question 1

Factors to keep the same in speed experiments

Answer 1

same surface
force at launch
intial speed’

Question 2

Explain how a falling object can reach terminal velocity

Answer 2

• heres a downward force e.g weight
• accelerates downwards
• air resistance increases > weight
• deceleration
• drag=weight (resultant force decreases)
• acceleration decreases
• balanced forces + resultant force=TV = 0

Question 3

explain how the upward acceleration changes during the first few seconds

Answer 3

speed increases
drag starts to increase
downward force increases

Question 4

what part of DTG can be used to calc speed?

Answer 4

gradient or slope

Question 5

Two forces ALWAYS opposing motion and opposing motion of falling object

Answer 5

friction
air resistance

-SA and speed

Question 6

Explain how reducing weight would affect the upward acceleration

Answer 6

weight decreases
unbalanced force increases
mass decreases

Question 7

Explain hwo to investigate wheter a spring obeys hooks law

Answer 7

measure original length
add the known weight
mesaure the new length
repeat for range of values of load
expiremntal detail (same start meausure place)

Question 8

differenec between vector and scalar quantity and examples

Answer 8

V = mag + direction e.g velocity/acc/force
S = Mag ONLY e.g time/energy/dist

Question 9

effects of forces

Answer 9

• can change speed,shape and direction (N)
• types of forces e.g electrostatic and gravitational
• F= ma

Question 10

how to find resultant force along same line

Answer 10

• add together if in the same direction

- subtracted if in different directions

Question 10

whats newtons first law + second + third law

Answer 10

• an object has constant velocity unless acted on by a resultant force
• F = ma
• every action force has an equal and opposite reaction force

Question 11

relationship between weight, mass and gfs

Answer 11

• mass = measure of total matter in an object (Kg)
• weight = effect of gf on a mass
• W = mg
• GFS on earth is 10 (9.8N)

Question 12

SD = TD + BD thinsg that effect stopping dist

Answer 12

• greater speed or mass
• slow reaction time cuz of alc/tiredness/distractions
• poor road conditions (icy/wet)
• poor car conditions (worn tires/worn brakes)

Question 13

hooke’s law

Answer 13

• F= kx
• extension is directly proportional to force applied
• Force applied = spring constant x extension

Question 14

hookes law on straight line graph v curved line graph

Answer 14

• point it stops being straight = limit of proportionality (no longer obeys HL)
• Gradient is spring constant/k
• not following HL
• after this region = fracture

Question 15

hookes law practical

Answer 15

measure original length
add the known weight
mesaure the new length
repeat for range of values of load
expiremntal detail (same start meausure place)