TYS 'O' LVL physic questions

• gunner77

  18 Oct 08, 20:18

  3(a) a car travels round a circular track at a constant speed of 40km/h

          explain why the car's velocity is not constant?

  3(b) is the car accelerating? explain your answer

• tinuviel07

  18 Oct 08, 20:21

  Originally posted by gunner77:

  3(a) a car travels round a circular track at a constant speed of 40km/h

          explain why the car's velocity is not constant?

  3(b) is the car accelerating? explain your answer

  velocity composed of both magnitude and direction. since it is travelling around a circular track, the direction of the velocity is changing. hence the velocity is not constant even though the magnitude is.

   

• gunner77

  18 Oct 08, 20:23

  wat is magnitude?

• tinuviel07

  18 Oct 08, 20:23

  the numerical value..

• gunner77

  18 Oct 08, 20:24

  huh?

  can tell me in simpler terms?

• crucifiedx

  18 Oct 08, 20:25

  i was thinking of asking this ques from tys also.. haha.

• tinuviel07

  18 Oct 08, 20:25

  if the speed increases from 2km/h to 5 km/h then down to 1 km/h, there is a change in its magnitude.. ? sorry i don't teach physics so not sure of more precise terms they use to teach students

   

  that means the numerical value change lah

• gunner77

  18 Oct 08, 20:27

  ohh, the number change la?

  then part B is wat?

• tinuviel07

  18 Oct 08, 20:28

  yup there's acceleration

• tinuviel07

  18 Oct 08, 20:29

  if the direction of acceleration is same as velocity, then is acceleration. if the direction is opposite, then is deceleration.. eagle come explain lah

• gunner77

  18 Oct 08, 20:29

  Originally posted by tinuviel07:

  yup there's acceleration

  
  why?

• tinuviel07

  18 Oct 08, 20:30

  acceleration is change in velocity over time. since velocity is not constant (changing) means acceleration is there lor

• gunner77

  18 Oct 08, 20:31

  Originally posted by tinuviel07:

  if the direction of acceleration is same as velocity, then is acceleration. if the direction is opposite, then is deceleration.. eagle come explain lah

  
  hmm interesting...

   

• gunner77

  18 Oct 08, 20:31

  actually i also donno why im doing physic when chemistry is on monday

• tinuviel07

  18 Oct 08, 20:33

  exciting ma.. jump here jump there..

   

• gunner77

  18 Oct 08, 20:34

  nvm, tmr i practise chem, if got doubts i will post, tin tin must help me ok?

• tinuviel07

  18 Oct 08, 20:35

  haha okayyy if i'm at home

• gunner77

  18 Oct 08, 20:36

  accounts is ur master subject rite?

• tinuviel07

  18 Oct 08, 20:38

  hmmm so so lor.. i prefer maths n chemistry.. accounts bo bian have to know

• gunner77

  18 Oct 08, 20:40

  ok la

  i go watch football liao

  tmr then study.

  i love to procrastinate

• deteq

  18 Oct 08, 21:08

  eh wait. i think the answer to 3b is zero acceleration since the car is travelling at a constant speed. constant speed means no acceleration.

• tinuviel07

  18 Oct 08, 21:10

  acceleration is the rate of change in velocity. since the velocity is not constant, there is acceleration

• Occam's Razor

  18 Oct 08, 21:14

  The car is moving in circles, so the velocity is always changing. As velocity is not constant, the car IS accelerating.
  
  deteq, acceleration is dependent on velocity(vector) not speed(scalar).
  
  (This Q actually appeared in one of the prelim papers I've done, so the answer should be correct)

   

• deteq

  18 Oct 08, 21:17

  so it is acceleration and not decceleration?

• tinuviel07

  18 Oct 08, 21:18

  it depends on the direction of velocity as compared to direction of acceleration as i've mentioned earlier