13 . Solving Problems Rewrite F=Bqv to find v in terms of F,q, and B.
14. Critical Thinking Using values given in a problem and the equation of distance = speed x time, you calculate a car’s speed to be 290 km/h. Is this a reasonable answer? Why or why not? Under what circumstances might this be a reasonable answer?
The Correct Answer and Explanation is
13. Solving Problems: Expressing v in Terms of F, q, and B
We start with the given equation:
[
F = Bqv
]
To solve for ( v ), we divide both sides by ( Bq ) (assuming ( B \neq 0 ) and ( q \neq 0 )):
[
v = \frac{F}{Bq}
]
Thus, the equation rewritten in terms of ( v ) is:
[
v = \frac{F}{Bq}
]
14. Critical Thinking: Evaluating a Car Speed of 290 km/h
A calculated car speed of 290 km/h is quite high compared to typical speeds of regular road vehicles. Let’s analyze whether this value is reasonable.
Is This a Reasonable Answer?
For most cars, 290 km/h (180 mph) is an extremely high speed, far exceeding speed limits on public roads and highways. Most regular sedans and SUVs have top speeds between 160–220 km/h (100–140 mph). Therefore, for an average car in a typical driving situation, this speed is not reasonable.
Additionally:
- Legal restrictions: Most countries have maximum speed limits ranging from 100–130 km/h (60–80 mph).
- Safety concerns: Driving at 290 km/h on public roads is dangerous due to reaction times, braking distances, and road conditions.
- Fuel efficiency: At such speeds, fuel consumption increases dramatically, making it inefficient.
Under What Circumstances Might This Be Reasonable?
There are some scenarios where 290 km/h could be possible:
- Supercars and Hypercars – High-performance cars like the Bugatti Chiron, Lamborghini Aventador, or Ferrari SF90 can reach or exceed 290 km/h.
- Professional Racing – In motorsports, such as Formula 1 or NASCAR, cars frequently exceed this speed.
- Autobahn (Germany) – Some sections of the German Autobahn have no speed limit, allowing high-performance vehicles to reach such speeds legally.
- Test Track or Closed Circuit – Car manufacturers test high-speed vehicles on dedicated tracks under controlled conditions.
Conclusion
While 290 km/h is not a reasonable speed for everyday driving, it is achievable under special conditions, such as with high-performance cars, professional racing, or on certain unrestricted roads.