The answer is A because An Indicator" changes color when it comes in contact with an acid or a base
An indicator could be anything like:
1) Litmus paper
2) Bromothymol blue
3) Phenolphthalein
Answer;
B. Fluorescent lamps operate at a higher temperature than incandescent lamps.
Explanation;
-A fluorescent lamp, is a type of electric light (lamp) that uses ultraviolet emitted by mercury vapor to excite a phosphor, which emits visible light.
-A fluorescent lamp produces less heat, thus, it is much more efficient. A fluorescent bulb can produce between 50 and 100 lumens per watt. This makes fluorescent bulbs four to six times more efficient than incandescent bulbs.
-Fluorescent lamps operate best around room temperature. At much lower or higher temperatures, efficacy decreases.
v = x/t
v = average velocity, x = displacement, t = elapsed time
Given values:
x = 6km south, t = 60min
Plug in and solve for v:
v = 6/60
v = 0.1km/min south
Time stops everything is made out of atoms so if atoms freeze everything freezes
Answer:
Al's mass is 102.92 kg
Explanation:
As there are no external forces in the horizontal direction, the horizontal net force must be zero:
As the force is the derivative in time of the momentum, this means that the horizontal momentum is constant:

where the suffix i and f means initial and final respectively.
The initial momentum will be:

But, as they are at rest, initially


So, this means:

We know that the have an combined mass of 195 kg:
.
so:
.





Now, we can use the values:


where the minus sign appears as they are moving at opposite directions


and this is the Al's mass.