In: Physics
A car is traveling down the expressway at 31.7 ? with no acceleration. How far has the car? traveled in 3.9 hours? If the speed limit in such expressway is 70mph, should the driver receive a speed ticket?
A car is traveling down the same expressway as in the previous problem, it is traveling at 22.3 7 ?. If it constantly accelerates at a rate of 4.3 ?, in how many minutes is it going to pass the speed limit.
Hi buddy!
Let me try and help you solve this problem!
In the first case, the car is said to be travelling down the expressway at 31.7 mph (without any acceleration). So how far has it travelled in 3.9 hours = 31.7 3.9 = 123.63 miles. And NO! since the vehicle is not accelerating, the speed will remain constant throught its journey. And since the speed is already mentioned to be 31.7 mph, it is well below the speed limit of 70mph. So the driver will not recieve a speeding ticket!
Second case.
Well here the car is travelling at 22.37 mph and constantly accelerates at 4.3 mph. In how many minutes is it going to cross the speed limit,
Here initial velocity (u ) = 22.37 mph
take final velocity (v) = 70 mph
and acceleration (a) = 4.3
Now to calculate the time (t), plug into simple formula V = u + at
This gives, 70 = 22.37 + 4.3 t
4.3 t = 70 - 22.37 = 47.63
Thus, t = 11.076 min is the required solution
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