Explanation:
Niels Bohr improved Rutherford's model. Using mathematical ideas, he showed that electrons occupy shells or energy levels around the nucleus. The Dalton model has changed over time because of the discovery of subatomic particles .
The upward force of the chain on the diamond would be the tension in the chain, and this tension would have to support the weight of the 45g that hangs from the chain.
mass = 45 g = 45/1000 kg = 0.045kg
Weight = mg = 0.045 * 10 ≈ 0.45N, g ≈ 10 m/s²
<span>So the upward force is ≈ </span><span>0.45N. </span>
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.
Answer:

Explanation:
Given:
- mass of John,

- mass of William,

- length of slide,

(A)
height between John and William, 
<u>Using the equation of motion:</u>

where:
v_J = final velocity of John at the end of the slide
u_J = initial velocity of John at the top of the slide = 0
Now putting respective :


<u>Now using the law of conservation of momentum at the bottom of the slide:</u>
<em>Sum of initial momentum of kids before & after collision must be equal.</em>

where: v = velocity with which they move together after collision

is the velocity with which they leave the slide.
(B)
- frictional force due to mud,

<u>Now we find the force along the slide due to the body weight:</u>



<em><u>Hence the net force along the slide:</u></em>

<em>Now the acceleration of John:</em>



<u>Now the new velocity:</u>



Hence the new velocity is slower by
