Question

if a velocity time graph, if it goes beow the x=0 line.
how do you describe that motion?
is it goin back or something? :S

Answer 1

yes

Answer 2

provided the x axis is the time

Answer 3

Velocity has direction, so a positive value is motion in one direction and negative values, motion in the opposite direction

Answer 4

ok, thanks :)
do you know whether speed = the same as acceleration??
is it the same thing?

Answer 5

No. Speed is like velocity except that it doesn't include direction. In other words, if I'm going backwards at 5mi/hr, I have a velocity of -5 but a speed of 5.

Acceleration is an expression of how quickly your velocity is changing. If I'm going 80 mi/hr, but not speeding up or slowing down, I have 0 acceleration. If I'm at a stop sign and I put my foot on the gas, now I have acceleration because my car is speeding up.

Answer 6

what is it then???

Answer 7

It? What is what?

Answer 8

you said no
so that means im wrong and it isnt going backwards

Answer 9

so what is it then if not backwards?
:S

Answer 10

On a velocity time graph, negative velocity represents going backwards.

Answer 11

You just incorrectly used speed and velocity to mean the same thing. They don't. Neither do velocity and acceleration mean the same thing.

On your velocity time graph, acceleration is the slope of your line.

Answer 12

If you're speeding up very quickly, your velocity increases rapidly, so your graph has a big slope. If you're slowing down, your velocity decreases, so the slope is negative.

Answer 13

oh, lol
i didnt see that question :S
i thought that i asked it somewhere else

so acceleration and velocity is different, right?
im getting so confused with this homework :@

Answer 14

Miss, have you ever ridden a bicycle or driven a car?

Answer 15

bicycle yes, car no

Answer 16

okay. have you ever sped up on your bicycle?

Answer 17

yes

Answer 18

okay. when you speed up, you are accelerating. when you go at the same speed, you are not accelerating.
in other words, accelerating defines how fast you are speeding up. If you pedal really hard, your speed increases rapidly. you pedal gently, your speed increases slowly.
when you apply brakes, you are slowing down from a higher speed to a lower speed. That is also acceleration, but it is negative acceleration or deceleration. in other words, it is how fast you slow down. if you apply the brakes real hard, you come to a stop very quickly, but if you gently press the brakes, you slow down gently. acceleration or deceleration measure how fast you speed up or slow down

Answer 19

ok, thanks :)
thanks for the detailed explanation, it helped

Answer 20

you are welcome