our dynamic universe pt.1

Question 1

acceleration

Answer 1

the change in velocity per unit time

Question 2

acceleration units

Answer 2

ms^-2

Question 3

newtons 1st law

Answer 3

an object will remain at rest, or continue with a constant velocity in a straight line, unless acted upon by an unbalanced force

Question 4

newtons 2nd law

Answer 4

F=ma

Question 5

resolving vectors mnemonic

Answer 5

CHAVS (cos horizontal and vertical sin)

Question 6

Vv

Answer 6

vsinx

Question 7

Vh

Answer 7

vcosx

Question 8

law of the conservation of energy

Answer 8

energy cannot be created or destroyed, just changed from one form to another

Question 9

tension when the object is moving at a constant speed (acceleration is 0)

Answer 9

zero

Question 10

constant speed in terms of forces

Answer 10

balanced forces

Question 11

force on a slope equation

Answer 11

F=mgsinx

Question 12

momentum units

Answer 12

kgms^-1

Question 13

law of the conservation of momentum

Answer 13

the total momentum before is equal to the total momentum after, in the absence of external forces

Question 14

total energy in a collision

Answer 14

total energy is always conserved

Question 15

kinetic energy in a collision

Answer 15

kinetic energy is only conserved in an elastic collision, not in an inelastic collision

Question 16

impulse

Answer 16

the change in momentum

Question 17

impulse units

Answer 17

kgms^-1 or Ns

Question 18

impulse, vector or scalar

Answer 18

vector

Question 19

energy, vector or scalar

Answer 19

scalar

Question 20

another way to calculate impulse

Answer 20

the area under a force-time graph

Question 21

converting ms to s

Answer 21

divide it by 1000

Question 22

explain why the tension in each rope increases when an angle is added

Answer 22

tension now has a horizontal component, vertical component of tension is unchanged

Question 23

improving reliability of an experiment

Answer 23

repeat measurements, use additional (gratings)

Question 24

a cable breaks when a drone hovers at a constant height, describe the vertical motion

Answer 24

accelerates upwards as upwards force is greater than weight

Question 25

explain in terms of forces why a terminal velocity may be reached

Answer 25

frictional force increases and this and the weight become balanced