Question

Anybody here good at physics and curious to know how long it takes a speeding Moped to reach Ke$ha?

Answer 1

The moped accelerates uniformly over a time of 5.21 seconds for a distance of 110 meters. I have to a) find the average velocity, b) find the velocity at 5.21 seconds, and c) determine acceleration of the Moped.

Answer 2

I'm pretty sure that the average velocity is 21.11 m/s (distance/time), but I'm unsure how to solve the others. Help?

Answer 3

does the moped start from rest?

Answer 4

I'm assuming so

Answer 5

My formula chart sez
\[\Delta d = v_i \Delta t + \frac{1}{2}a (\Delta t)^2\]
and you know d, v_initial, and t, so it's easy to solve for "a" ...

Answer 6

average velocity= (u+v)\2=21.21 m\s
v=u+at
u+v=42.22 m\s

Answer 7

final velocity is pretty fast, can we hope that Ke$ha won't be able to get out of the way of the speeding moped?

Answer 8

42.22-u=u+at
2u=42.22-5.21 a

Answer 9

lol @ fixer... but your formula is way too intense for me :) I think that there's a way to figure it out without one other than the basics...

Answer 10

ravi: what do u and v stand for?

Answer 11

i think ravi is saying that final velocity is twice average velocity (since initial velocity is zero), and than acceleration is (final velocity) / (time).

Answer 12

a=(42.22-2u)\2
u=initial velocity
v=final velocity

a=acceleration

Answer 13

hold on... let me process that information...

Answer 14

ravi- how'd you get 21.21? My calculations give 21.11

Answer 15

sir, it was written by mistake

Answer 16

okay, so it is 21.11? and then from there you said that velocity=initial velocity + acceleration * time?

Answer 17

yeah

Answer 18

and after that was initial velocity + final velocity= 42.22 m/s. Where did 42.22 come from?

Answer 19

everyone whos good at physics are at physics group

Answer 20

no one in the physics group :P

Answer 21

distance traveled=(average velocity). time=110

Answer 22

im glad some one could help u

Answer 23

20ppl there

Answer 24

Ravi? Where's u go :(

Answer 25

i am here

Answer 26

u+v=42.22
v-u=5.21 a
so adding these equation, we get
2v=42.22+5.21a

Answer 27

v=(42.22+5.11a)\2

Answer 28

a=(v-u)\t
if moped started from rest then
a=v\t=v\5.11

Answer 29

now we have final equation for v
v=( 42.22+5.11*(v\5.11) ) \ 2
solving this equation for v, we can find the value of final velocity .

Answer 30

here average velocity= (u+v)\2