1. Make an observation
2. Form a question
3. Form a hypothesis
4. Conduct an experiment
5. Analyze the data and draw your conclusion
I think u would add them all up and then write down your answers
The speed after 21 s is 18.9 m/s and the total time required for the train to reach a speed of 34 m/s is 14.4 s
<h3>
What is Speed ?</h3>
Speed is a distance travelled by a body per time taken. It is a scalar quantity and it is measured in m/s
Given that at Initially stationary, a train has a constant acceleration of 0.9 m/s2.
(a) What is its speed after 21 s?
- Acceleration a = 0.9 m/s²
Using v = u + at
Substitute all the parameters into the equation
v = 0 + 0.9 x 21
v = 18.9 m/s
(b) What is the total time required for the train to reach a speed of 34 m/s?
Let first calculate for total distance by using
v² = u² + 2as
34² = 18.9² + 2 × 0.9 × S
1156 = 357.21 + 1.8S
1.8S = 1156 - 357.21
1.8S = 798.79
S = 798.79 / 1.8
S = 443.8 m/s
v = u + at
34 = 21 + 0.9t
0.9t = 34 - 21
0.9t = 13
t = 13/0.9
t = 14.44s
Therefore, its speed after 21 s is 18.9 m/s and the total time required for the train to reach a speed of 34 m/s is 14.4 s
Learn more about Speed here: brainly.com/question/24739297
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Answer:
we cannot view through an opague object since it does not alow light through but only cast shadows
Explanation:
Answer:
Explanation:
In series the resistance of combination is large, so if the resistance is more, the current will be less and we will have less shock.
In parallel, the combined resistance is less than the individual resistances so the current is more and we will have more shock.
So we should prefer series connection