Answer:
D) The heavier ball will have a higher temperature because the change of temperature is inversely proportional to mass.
Explanation:
As stated in the problem, the amount of heat released by each ball is

where
m is the mass of the ball
Cp is the specific heat of iron (so, it is equal for both balls)
is the change in temperature of each ball
In this problem, we are said that the amount of heat released by the two balls, Q, is the same. Cp is also the same: this means that the product
must be the same for the two balls. So, the mass and the change in temperature are inversely proportional: therefore, the heavier ball will have a smaller change in temperature. And since both balls starts from the same temperature, 100 C, this means that the heavier ball will reach a higher temperature than the lighter ball.
In a stationary situation, the weight of person is

This is the weight "felt" by the scale, which is basically the normal reaction applied by the scale on the person, and which uses the value of g (9.81) as reference to convert the weight (602.8 N) into a mass (62 kg).
When the person is in the elevator, the scale says 77 kg. The scale is still using the same value of conversion (9.81), so the apparent weight "felt" by the scale is

This is the normal reaction applied by the scale on the person, and which is directed upward. Besides this force, there is still the weight W of the person, acting downward. So, if we use Newton's second law:


where a is the acceleration of the elevator. If we solve for a, we find

The negative sign means the acceleration is in the opposite direction of g (which we take positive), so it means the elevator is going upward.
Answer:
4. B and D
Explanation:
Two points along a transverse wave (such as the one in the figure) are said to be in phase when:
- the vertical position of the two points is the same
- The oscillation of the wave is going in the same way for both points
Basically, we say that two points are in phase when they are separated by a complete cycle (one complete oscillation) of the wave.
For this wave, we see that point B and C have same displacement, but they are not in phase since in B the oscillation is going down while in C is going up.
Instead, B and D are in phase, because they are separated by one complete cycle: both points have same displacement and the oscillation is going in the same way for both of them.
Answer:
when a element of 1 group take part in reaction, its atom looses outer electron and form positively charged ions called Cation.
Explanation:
The colder the more likely it is to become a liquid