Respuesta :
Answer:
minimum speed of the car when the brakes locked is 16.15 m/s
Explanation:
given data
straight skid marks = 20.0 m
solution
we consider here mass of car is 1.20 × 10³ kg
and friction force is 7.83× 10³ N
so here acceleration will be
acceleration = force ÷ mass ................1
acceleration = [tex]\frac{7.83\times 10^3}{1.20\times 10^3}[/tex]
acceleration = 6.525 m/s²
and
speed after 20 m final speed v is 0 m/s
and here minimum speed of the car when brakes was locked is u m/s
so we apply equation of motion
v² - u² = 2 × a × s ............2
0 - u² = 2 × 6.525 × 20
solve it we get
u = 16.15 m/s
so minimum speed of the car when the brakes locked is 16.15 m/s
The minimum speed of the car when the brakes are locked is 16.15 m/s
Equation of motion:
Since the mass of the car is 1.20 × 10³ kg and friction force is 7.83× 10³ N
So, the acceleration should be
= force ÷ mass
[tex]= 7.83 \times 10^{3} \div 1.20 \times 10^{3}[/tex]
= 6.525 m/s²
Now the minimum speed should be
v² - u² = 2 × a × s
0 - u² = 2 × 6.525 × 20
u = 16.15 m/s
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