Question

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Answer 1

use the formula D=RT

Answer 2

yes correct so you would divide what to get T by its self

Answer 3

hmmmm

Answer 4

is that -7.5 minutes per second

Answer 5

oh ok

Answer 6

my best guess would be 6 seconds

Answer 7

what i would do is use the formula that i showed you and plug in the numbers but just to make sure im not giving you the wrong answer im going to have my friend help you @Elsa213

Answer 8

A car moving with a speed of 108 km/h is brought to rest in a distance of 60 m. The car's acceleration is -7.5 m/s/s. How much time did the car take to stop?

So the initial velocity of the car is 108 km/h
and it's brought to rest in a distance of 60m
and the cars acceleration is -7.5 m/s^2
t = ?

Now we have the formula \[d= v_0 t + 1/2 at^2\] now put it together.

Answer 9

No it doesn't, but this formula may be a bit too difficult for you atm as you would have to use quadratic formula, lets just make it simple on ourselves and use
\[v_f = v_i + at\]

Answer 10

Now solve for t

Answer 11

whats final and initial velocity thought

Answer 12

You should be able to figure that out, I actually posted it above.

Answer 13

The point of this problem is for you to figure out if you know all the quantities and what they mean.

Answer 14

Try setting it up, make sure you solve for t, and note that you have to convert your units to m/s!!

Try it out and if you get it wrong, don't worry I will help you then.

Answer 15

Ok, so reading this question `A car moving with a speed of 108 km/h is brought to rest in a distance of 60 m.` Notice how it says the car is brought to REST in a distance of 60m, so it's final velocity = 0, as it's at rest, and initial is 108 km/h.

Answer 16

You have to convert the 108 km/h though to m/s

Answer 17

This is why I said we need to read it carefully earlier :P

Answer 18

Right on, now solve for t.

Answer 19

Yup 4s is good!

Answer 20

Np :)