Answer:
a)
reaction time = 0.70 s
distance travelled in reaction time = v*t
= 20 m/s * 0.70 s
= 14 m
So, when brake is applied, distance remaining= 110 m - 14 m = 96 m
Answer: 96 m
b)
vf = 0 m/s
d = 96 m
vi = 20 m/s
use:
vf^2 = vi^2 + 2*a*d
0 = 20^2 + 2*a*96
-400 = 2*a*96
a = -2.08 m/s^2
Answer: -2.08 m/s^2
c)
use:
vf = vi + a*t
0 = 20 - 2.08*t
t = 9.6 s
Answer: 9.6 s
Explanation:
Answer:
Explanation:
Speed given = 125 m /min
125 /60 m /s
In 450 second it will travel
= 450 x 125 / 60
=937.5 m.
As the distance is covered in less than 450 seconds , The distance must be less than 937.5 m
In 400 seconds , it will travel
= 400 x 125 / 60
833.33 m
Since the distance is covered in more than 400 seconds , the distance must be more than ie 833.33 .
Hence the distance covered is more than .833 m but less than 937.5
In either case these distance are more than .8 km .
Normal force is mass x gravity, so mass x 9.81
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