Question

A skater traveling at 7 m/s accelerates at the rate of .80m/s/s for an interval of 2.0sec. What is the final velocity?

***thank you!! :)

Answer 1

any ideas?

Answer 2

f=m*a ?

not sure :/

Answer 3

v= a*t

Answer 4

what is the formula which gives the velocity of an object in acceleration?

Answer 5

@iheartfood

Answer 6

ohh okay!

so 7*2?

or is it 7*0.8 ?

Answer 7

for v=a*t?

Answer 8

hint, your formula is:
\[v(t)=v _{0}+a*t\]
where v_0 is the initial velocity @iheartfood

Answer 9

you should try to match units.
also, strictly speaking, v=at is the change in velocity
so we add that to the original velocity (if any)

Answer 10

if we look only at the units
velocity is m/s
acceleration is m/s^2
notice m/s^2 * s (i.e. a * t) gives units of m/s (velocity)

Answer 11

ohh so i would want to do 7 m/s * 0.8 m/s ?

Answer 12

and what would v0 be? :/

Answer 13

v_0=7m/sec

Answer 14

that would give m^2/s^2 and that is not velocity

Answer 15

ohhhh

wait so what would it look like to substitute?

7 + 0.8 * 2 ?

so 7+1.6 = 8.6 ?

Answer 16

that's right!

Answer 17

oh! so that would be the final velocity?

like this? 8.6 m/s^2 ?

Answer 18

yes, but with these problems always put in the units. (It is safer that way, and helps keep things clear)

Answer 19

ahh okie! :) and it would be m/s^2 for the final velocity? :O

Answer 20

no, unit of measure of velocity is m/sec

Answer 21

and you should be m/s as the final units (velocity is distance divided by time, e.g. meter/seconds

Answer 22

ohh so it's 8.6 m/s ? :)

Answer 23

ok!

Answer 24

okay! awesome!! thank you both!! @phi @Michele_Laino :)

Answer 25

thank you! @phi @iheartfood :)

Answer 26

distance : m
velocity = m/s
acceleration : (m/s)/s
jerk : ((m/s)/s)/s
...

Answer 27

sorry, what is "jerk" please ? @ganeshie8

Answer 28

http://en.wikipedia.org/wiki/Jerk_%28physics%29

Answer 29

ok! thanks! for your answer @ganeshie8

Answer 30

it is used very rarely i guess..

Answer 31

yes! that's true!
It is mye first time that I see it

Answer 32

oops...it is my first time...