041087

點計?豪無IDEAL,唔知點落手！

[ 本帖最後由 Potato2139611 於 2011-6-30 07:48 PM 編輯 ]

yeungwk91

rest => v=0 => t=0s(rej.) or t=3s
do the intergration

s = in v dt
=3t^2 -t^3/3

the sub t=3 into s
s= 27-9 = 18m

041087

引用:

原帖由 yeungwk91 於 2011-4-10 01:26 AM 發表
rest => v=0 => t=0s(rej.) or t=3s
do the intergration

s = in v dt
=3t^2 -t^3/3

the sub t=3 into s
s= 27-9 = 18m

the answer is 4.5

Chrix

我都想知點做

yeungwk91

sor
I do the integration wrong
rest => v=0 => t=0s(rej.) or t=3s
do the intergration

s = in v dt
=3t^2 / 2 -t^3/3

the sub t=3 into s
s= 13.5-9 = 4.5 m

Chrix

我想問E題係邊個TOPIC同埋係F.幾既PHY?

yeungwk91

it is not physics
it is M1/M2 (I think)

桃子

If you haven't learnt integration, it would be impossible for you to do this question.

041087

引用:

原帖由 桃子 於 2011-4-10 09:17 PM 發表
If you haven't learnt integration, it would be impossible for you to do this question.

can u teach me how to do it?

041087

引用:

原帖由 桃子 於 2011-4-10 09:17 PM 發表
If you haven't learnt integration, it would be impossible for you to do this question.

CAN U TEACH ME HOW TO DO IT?

yeungwk91

DO u know calculus?

041087

引用:

原帖由 yeungwk91 於 2011-4-11 11:33 AM 發表
DO u know calculus?

yes

yeungwk91

Differentiation :
displacement -> velocity -> acceleration

integration:
displacement <- velocity <- acceleration

game8807

distance = velocity x time

d=vt

不過今次個v係denpend on time 所以要用integation 黎計

前面d 人都做得啱