- #1

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I have already found the answer to be 5 meters between me and the deer and now it wants me to "Determine the time required for you to stop once you hit the brakes. Im confused on how to get this value. Any help would be appreciated. Thanks

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- Thread starter andyman21
- Start date

- #1

- 13

- 0

I have already found the answer to be 5 meters between me and the deer and now it wants me to "Determine the time required for you to stop once you hit the brakes. Im confused on how to get this value. Any help would be appreciated. Thanks

- #2

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Vi = 20 m/s

Vf = 0.0 m/s

d = 35 m

Tr = 0.50 s

a = -10 m/s^2 --> Note this must be negative, as acceleration is "acting against" your line of travel. if it isn't, your math won't work.

First calculate how far you travel before you hit the brakes. This is easy, 6th grade math. Distance, rate, time.

D = R * T

D = Vi * Tr

D = (20 m/s) * (0.50 s)

D = 10 m

Second, how far you went after you hit the brakes.

Dd = [ Vf^2 - Vi^2 ] / [ 2 * (-10 m/s^2) ]

Dd = [ (0.0 m/s)^2 - (20 m/s)^2 ] / (-20 m/s^2)

Dd = [ -400 m^2/s^2 ] / (-20 m/s^2)

Dd = 20 m

Total distance traveled

Dt = D + Dd

Dt = (10 m) + (20 m)

Dt = 30 m

Does he survive?

Ds = d - Dt

Ds = (35 m) - (30 m)

Ds = 5 m

So you come to a stop 5 meters before hitting him

- #3

PhanthomJay

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- #4

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Would i plug my answer of 5m into say d=vi+vf/2xt ( so it would be 5=20+0/2xt?)

- #5

PhanthomJay

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