This is easily explained saying that the frictional force between the books and the paper isn't big enough to produce a displacement in the books. The displacement in the books doesn't happen because the frictional force between the books and the surface they are standing on is bigger than the paper's one.
It's been a while since I've studied this, but my answers would be:
13. 5730 years. The half-life of a substance is the amount of time it takes for half of it to decay, and, according to the graph, half of the substance remained at 5730 years.
14. 10740 years. According to the graph, only 25% of the carbon remained after 10740 years.
15. 15 atoms. According to the graph, only 12.5% of the carbon remained after 16110 years. 12.5% of 120 atoms is 15 atoms.
16. 1600 atoms. According to the graph, if a sample of carbon is 10740 years old, only 25% of it remains. To find the original amount, multiply the current amount by (100% / 25%), which equals 4. So, 4. 400 atoms * 4 = 1600 atoms is the original amount.
The resistance of the lamp plugged in to a standard wall outlet with a current of 0.5 amps is 240 Ω (ohms)
Explanation:
In the United States Of America the standard voltage is 120 v and their frequency is 60 Hz
Standard wall outlet voltage is 120 V
The current in the lamp is 0.5 ampere
Resistance (R) = V/ I
= 120/0.5
= 240Ω (ohms)
Thus the resistance of the lamp plugged in to a standard wall outlet with a current of 0.5 amps is 240 Ω (ohms).
Answer:
C. 
Explanation:
Let initial charges on both spheres be,
When the sphere C is touched by A, the final charges on both will be,
#Now, when C is touched by B, the final charges on both of them will be:
Now the force between A and B is calculated as:
Hence the electrostatic force becomes 3F/8
(1500 rev/min)(min / 60 s) / (3.0 s) = 8.33 rev/s²
<span>(B) </span>
<span>(1/2)(8.33 rev/s²)(3.0 s)² = 37.5 rev </span>
<span>(C) </span>
<span>(1500 rev/min)(min / 60 s)[2π(0.12 m) / rev] = 18.8 m/s</span>
