Thursday

April 2, 2015

April 2, 2015

Posted by **Sarah** on Friday, October 11, 2013 at 2:36am.

Determine the stopping distances for an automobile with an initial speed of 89 km/h and human reaction time of 2.0 s for the following:

(a) an acceleration a = -4.0 m/s2.

(b) a = -8.0 m/s2.

- Physics -
**Henry**, Saturday, October 12, 2013 at 10:12pmVo=85000m/h = 85000m/3600s = 23.61 m/s.

a. V = Vo + a*t

T = (V-Vo)/a + Tr

T = (0-23.61)/-4 + 2s = 7.9 s = Stopping time.

d = Vo*t + 0.5a*t^2

d = 23.61*7.9 + 0.5*-4*7.9^2 = 61.7m

b. T = (0-23.61)/-8 + 2s = 4.95 s.

d=23.61*4.95 + 0.5*(-8)*4.95^2=18.86 m.

- Physics -
**Henry**, Saturday, October 12, 2013 at 10:44pmCORRECTION:

Vo=89,000m/1h = 89000/3600s = 24.72 m/s

a. V = Vo + va*t

T = (V-V0)/a + Tr

T = (0-24.72)/-4 + 2s.=8.18 s.=Stopping

time.

d = Vo*t + 0.5a*t^2

d=24.72*8.18 + 0.5*(-40*8.18*2=68.38 m.

b. T = (0-24.72)/-8 + 2s = 5.09 s.

d=24.72*5.09 + 0.5*(-8)*5.09^2= 22.19 m.

**Answer this Question**

**Related Questions**

Physics - I really don't get why I am getting this question wrong? Please can ...

Physics - I really don't get why I am getting this question wrong? Please can ...

Physics - I really don't get why I am getting this question wrong? Please can ...

Algebra help - f(x)=x^3-4x^2-x+4 How do I find the x-intercept for this? This is...

chemistry - This question I really don't get it. I tried tried tried to figure ...

algebra - Solve by substitution method 3x+8y=17 2x+y=14 please show step by step...

Physics - I'm trying to rearange this 0 = Xo + 2^-1 a t^2 for t I've been told ...

Physics - Can someone please show me step by step how to normalize e^-5x in the ...

Math - 2(5x + 1) = 3(3x + 7) a) x = 19 b) x = 20 c) x = 21 Can you please ...

chemistry - Can someone please explain how to do this question? A 0.057M ...