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prisoha [69]
3 years ago
9

Haley is driving down a straight highway at 73 mph. A construction sign warns that the speed limit will drop to 55 mph in 0.50 m

i.
What constant acceleration (in m/s2) will bring Haley to this lower speed in the distance available?
Physics
2 answers:
Vadim26 [7]3 years ago
7 0

Answer:

0.29\text{m}\text{s}^{2}

Explanation:

Given: Haley is driving down a straight highway at 73 mph. A construction sign warns that the speed limit will drop to 55 mph in 0.50 mi.

To Find: constant acceleration (in \text{m}\text{s}^{2}) that will bring Haley to this lower speed in the distance available

Solution:

we know that,

1 mile=1.609km

1 km\setminush = 5\setminus18 m\setminus s

Initial Speed of Haley(u)=73 mph

                                     73\times 1.609\times 5\setminus 18

                                     32.63\text{m}\setminus\text{s}

Final Speed of Haley(v)= 55 mph

                                     55\times 1.609\times 5\setminus 18

                                     24.58\text{m}\setminus\text{s}

The distance to be travelled  while lowering the speed(S)=0.5 mile

                                     0.805 km

                                     805 m

according to third equation of motion,

                     \text{v}^{2}-\text{u}^{2}=2\text{a}\text{S}

as speed is lowering down the acceleration will be in the opposite direction of motion, hence acceleration will be negative, equation will become

                    \text{u}^{2} -\text{v}^{2}=2a\text{S}

putting values,

                     32.63^{2}-24.58^{2}=2a\times805

                     a=460.55\setminus1610

                     a≅0.29\text{m}\text{s}^{2}

the constant acceleration that will drop speed to 55 \text{mph} is 0.29\text{m}\text{s}^{2}

                                                                                                                                   

gulaghasi [49]3 years ago
3 0

Picture is my answer

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