Answer: C. the rod gains mass and the fur loses mass.
Explanation:Atomic particles have mass. The electron has a mass that is approximately 1/1836 that of the proton and with exchange exchange of charge this is also factored in. The movement of effect described above is known as the triboelectic charging process—charging by friction—which results in a transfer of electrons between the two objects when they are rubbed together. Plastic having a much greater affinity for electrons than animal fur pulls electrons from the atoms of fur, leaving both objects with an imbalance of charge. The plastic rod would have an excess of electrons and the fur has a shortage of electrons. Having an excess of electrons, the plastic is charged negatively and has more mass. In the same vein, the shortage of electrons on the fur leaves it with a positive charge and consequently with lesser mass.
Really, Gundy ? ! ?
The formula for the car's speed is given and discussed in the box. The formula is
v = √(2·g·μ·d)
Then they <em>tell</em> you that μ is 0.750 , and then they <em>tell</em> you that d = 52.9 m . Also, everybody knows that 'g' is gravity = 9.8 m/s² .
They also tell us that the mass of the car is 1,000 kg, and they tell us that it took 3.8 seconds to skid to a stop. But we already <em>have</em> all the numbers in the formula <em>without</em> knowing the car's mass or how long it took to stop. The police don't need to weigh the car, and nobody was there to measure how long the car took to stop. All they need is the length of the skid mark, which they can measure, and they'll know how fast the guy was going when he hit the brakes !
Now, can you take the numbers and plug them into the formula ? ! ?
v = √(2·g·μ·d)
v = √( 2 · 9.8 m/s² · 0.75 · 52.9 m)
v = √( 777.63 m²/s²)
v = 27.886 m/s
Rounded to 3 digits, that's <em>27.9 m/s </em>.
That's about 62.4 mile/hour .
