Question

I actually need help:

Answer 1

http://prntscr.com/38xp5c

Answer 2

v^2=vo^2+2ax can you use that?

Answer 3

may be start from here :

\(\large a = -16\)

Answer 4

and use below :

Integrating acceleration gives u velocity
integrating velocity gives u displacement

Answer 5

laughing out loud at batman.... showing off your physics talent

Answer 6

Guess calculus it is!

a = -16 here since it's deceleration, if you integrate acceleration you get v = -16t+ C

0 = -16t+C, where your c will represent initial velocity of the car at t = 0

X <- displacement

X = -16t^2/2 +Ct + C2, C2 = constant
X = -8t^2+Ct+C2
This is your displacement.

200 - -8t^2+ Ct, 200 because the car moves 200 feet before it stops

So we have 2 equations 0 = -16t+C, and 200 = 08t^2+Ct

0 = -16t+ C => C = 16t

Now we have 2 unkowns,

Can you do the rest?

Answer 7

You can also use energy methods.

Answer 8

\[
mah = \frac 12 mv^2
\]

Answer 9

200 = -8t^2 +(16t)t
200 = t^2
5 = t

C = 16t sub in 5 and boom you got your ft/s

Answer 10

using wio's conversation of energy :
http://www.wolframalpha.com/input/?i=16*200+%3D+1%2F2*+v%5E2

Answer 11

thank you luigi. thank you for sharing your problems to the world

Answer 12

Conservation of energy, soooo much quicker.

Answer 13

and cool too xD

Answer 14

I doubt he's allowed to use it though :o

Answer 15

but ye your answer is 80 ft/s

Answer 16

*Note to all: Has no physics background whatsoever*

Answer 17

So it is a math question?

Answer 18

Pray to batman, and it will come!

Answer 19

What did the math book tell you about these things?

Answer 20

it is a math question involving anti-derivatives

Answer 21

^

Answer 22

displacement, velocity, acceleration, jerk, skid... what are these mathematically

Answer 23

So are we doing the antideritative of Force with respect to work then?

Answer 24

with respect to distance^

Answer 25

Because that would be nice.

Answer 26

\[
\int_0^{200} 16m \;dx =3200 m
\]

Answer 27

Kinetic energy is the antiderivative of momentum with respect to velocity: \[
\int_0^{v_f}mv\;dv = \frac 12 m(v_f)^2
\]

Answer 28

Is that the work done, wio ?

Answer 29

ur first integral...

Answer 30

There, I can do anti-derivatives with energy methods as well.

Answer 31

a=-16