When a balloon is rubbed with a wool cloth, e<span>lectrons move from the atoms in the balloon to the atoms in the cloth, causing the cloth to have a negative charge. Therefore, the answer is B. Before they were rubbed together, they both had balanced charges. However, after rubbing them, the wool is left with the positive charge, and the balloon with the negative. This causes the atoms in the cloth to flow to the balloon, leaving the cloth with a negative charge.</span>
Answer:
The air resistance on the skydiver is 68.6 N
Explanation:
When the skydiver is falling down, there are two forces acting on him:
- The force of gravity, of magnitude 
, in the downward direction (where m is the mass of the skydiver and g is the acceleration due to gravity)
- The air resistance, 
, in the upward direction
So the net force on the skydiver is:
where
m = 7.0 kg is the mass
According to Newton's second law of motion, the net force on a body is equal to the product between its mass and its acceleration (a):
In this problem, however, the skydiver is moving with constant velocity, so his acceleration is zero:
Therefore the net force is zero:
And so, we have:
And so we can find the magnitude of the air resistance, which is equal to the force of gravity:
Answer:
500 Pa
Explanation:
Convert given units to SI:
100 dyne = 0.001 N
0.02 cm² = 2×10⁻⁶ m²
Pressure = force / area
P = 0.001 N / (2×10⁻⁶ m²)
P = 500 Pa
Answer:
the charge will be neutral.
Explanation:According a book, metals want to "lose" electrons to achieve noble gas configuration. But at the same time, copper ions in a galvanic element are going to gain electrons from a zinc electrode. Why is it so? Is it because one of them HAS to gain/lose electrons, and zinc wins out in terms of achieving noble gas configuration?
