LLD101

buttersdan · Posted: Mon Oct 09, 2006 6:47 pm Post subject: Physics question

Two objects A and B accelerate from rest with the same constant acceleration. Object A accelerates twice as long as object B. Which statement is true concerning these objects at the end of their respective periods of acceleration?

a. Object A will travel twice as far as object B.
b. Object A will travel four times as far as object B.
c. Object A will travel eight times further than object B.
d. Object A will be moving four times faster than object B.
e. Object A will be moving eight times faster than object B.

Please dont guess :S, and preferably explain why

krajee · Joined: 27 Aug 2004 Posts: 6579 9.68 Silvarrr

ra9e · Joined: 28 Jan 2006 Posts: 252 0.00 Silvarrr

if my brain serves me right "b" is the answer

assuming initial velocity is zero

the equation D=v1*t+(1/2)a*t^2 becomes (1/2)a*t^2

thus :

for A
Da=(1/2)a*(2t)^2 ---> D=(1/2)*a*4t^2

for B
Db=(1/2)a*t^2

i think i've done this question back in first year university physics -_-

buttersdan · Posted: Mon Oct 09, 2006 6:57 pm Post subject:

B is what i was thinking too, and i think gheed it is TIME

NightWish · Posted: Mon Oct 09, 2006 7:08 pm Post subject:

*pulls out 3 120page notebooks from physics.*
*relizes its to late*
*sits down and reads anyway.*

ZOMG PHYSICS ROXORZ!

buttersdan · Posted: Mon Oct 09, 2006 7:15 pm Post subject:

A trucker drives with an average velocity of 27 m/s toward the east on a perfectly straight highway. What will the trucker's displacement be after 2 hours?
a. 97 km to the east
b. 190 km to the east
c. 1600 km to the east
d. 3200 km to the east

okay how about this one, i got B on this, let me know if i got it right :S

Goky · Joined: 18 Feb 2006 Posts: 1425 1.68 Silvarrr

edits: oops, forgot to multiply by 2.

It's B.

buttersdan · Posted: Mon Oct 09, 2006 7:20 pm Post subject:

Which one?

NightWish · Posted: Mon Oct 09, 2006 7:20 pm Post subject:

Well since:
2 hours= 120 minututes=7200 seconds
The trucker travels 194400 meters which = 194.4 KM, or roughly B. Very Happy

NightWish · Posted: Mon Oct 09, 2006 7:23 pm Post subject:

How many calories does it take to heat 50ml of H2O +5 degrees kalvin at room temp (70degrees F).

Goky · Joined: 18 Feb 2006 Posts: 1425 1.68 Silvarrr

ra9e · Joined: 28 Jan 2006 Posts: 252 0.00 Silvarrr

NightWish · Posted: Mon Oct 09, 2006 8:10 pm Post subject:

Waramp · Joined: 02 Jun 2006 Posts: 4788 0.59 Silvarrr

kinematics was so easy in phys 100 last year. not looking forward to the energy portion next semester Sad

kinematics was easy cause i could visualize it, but its hard to visualize electricity

Icanneverwin · Posted: Mon Oct 09, 2006 9:18 pm Post subject:

You should ask b[x] via aim, he helped me with me physics hw when i was still a noob :0