Question

2. A car accelerates uniformly from +10.0 m/s to +40.0 m/s over a distance of 125 m. How long did it take to go that distance? Show all your work, including the equation used, given and unknown quantities, and any algebra required. Make sure your answer has the correct number of significant figures.

Answer 1

@AllTehMaffs can you help?

Answer 2

?

Answer 3

sure :) Has your professor gone over equations of motion in class?

Answer 4

well can you explain the problem and how you get your answer i'm home schooled

Answer 5

wait i got the answer.... can u help with another question???

Answer 6

Yeah, for sure. Sorry for the assumption :) Yeah, shoot for it. I'll see if I can get a reply out before you figure it out :)

Answer 7

4. A plane traveling at 300.0 km/h attempts to land on a 500 m runway. The plane’s engines and brakes accelerate uniformly at –5.0 m/s2. Will the plane be able to land safely? Show all your work. Include any equations used, the given and unknown. Show all calculations. Express numerical answers with the correct number of significant digits.

Answer 8

Cool. So you have to figure out if it takes more or less than than 500 meters for the velocity to equal zero.

Answer 9

i know can you help me figure this out?

Answer 10

Yeah, plug those numbers in to one of the basic equations of motion. In this case, we can use vf^2 = vi^2 = 2a (df-di) where vf and vi are the final and initial velocity, and df and di are the initial and final distances

Answer 11

a is acceleration

Answer 12

We don't need to know anything about the time that way

Answer 13

ok i dont't know where to plug the number can u show me

Answer 14

You need to solve for the final velocity. The initial velocity is 500 km/h. Your acceleration is -5m/s (notice the units) and your initial distance is zero, and your final is 500

Answer 15

500m

Answer 16

ok so whats the answer and equations to get the answer

Answer 17

The equation is above is what you need
vf = ?
vi = 300km/h (but you need to transform this into m/s)
a = -5 m/s^2
di = 0m
df = 500m

Answer 18

so it will land safley?

Answer 19

I haven't calculated it.

Answer 20

can u plz i really need help wuick i leave for my job soon

Answer 21

quick

Answer 22

? hello

Answer 23

=(?

Answer 24

wrong button
I don't think it will land safely

Answer 25

how much extra meets does it need to land safley

Answer 26

@AllTehMaffs

Answer 27

Do you need to know that? It's not in the problem... it'll still be going 44m/s when it hits the end of the runway

Answer 28

ok thanks!

Answer 29

dunno how many sig figs you needed :/

Answer 30

44.1