You oughtta be able to do this one.
The "efficiency" is just the portion of the input work that
comes out in a useful form.
If the efficiency is 70%, that tells you that however much work
you put INto the machine, the machine will do 70% of that much
work for you at the output side.
Put 20,000 J in ... out comes (0.70) x (20,000 J) = 14,000 J .
What happens to the other 30% of the work you put into it ?
It turns into HEAT. That's why machines always have to be
cooled somehow while they're running.
<u>Statement</u><u>:</u>
A force is required to accelerate a 600 g ball from rest to 14 m/s in 0.1 s.
<u>To </u><u>find </u><u>out</u><u>:</u>
The force required to accelerate the ball.
<u>Solution</u><u>:</u>
- Mass of the ball (m) = 600 g = 0.6 Kg
- Initial velocity (u) = 0 m/s [it was at rest]
- Final velocity (v) = 14 m/s
- Time (t) = 0.1 s
- Let the acceleration be a.
- We know the equation of motion,
- v = u + at
- Therefore, putting the values in the above formula, we get
- 14 m/s = 0 m/s + a × 0.1 s
- or, 14 m/s ÷ 0.1 s = a
- or, a = 140 m/s²
- Let the force be F.
- We know, the formula : F = ma
- Putting the values in the above formula, we get
- F = 0.6 Kg × 140 m/s²
- or, F = 84 N
<u>Answer</u><u>:</u>
The force required to accelerate the ball is 84 N and this force acts along the direction of motion.
Hope you could understand.
If you have any query, feel free to ask.
Answer:
Φ= 17 N•m²•C⁻¹
Explanation:
Gauss's Law states that electric flux equals the surface integral of E•dA. But since we are given all the variables as finite values, we can simplify it into EAcosφ.
-E is given as 95N/C
-A is simply (.4)(.6)=.24m²
-φ is the angle between the E field/vector and the normal/perpendicular vector to the surface. We know that E makes a 20° to the surface here, so the angle φ=(90-20)°=70°. So the E vector makes a 70° angle to the normal of the surface. (I can see this portion as being the point of confusion, as it was for me at first.)
With all that we can say that the flux Φ is:
Φ=(95)(0.24)(cos[70°])=17.4384... N•m²•C⁻¹
I'll approximate to 2 sigfigs in my answer, since that'd be the technical answer.
*I believe V/m are also correct units for electric flux.
Answer:
The answer is C. Resistance
Explanation:
Viggo needs to take an extended leave of absence from work for personal reasons. The remaining employees are required to perform Viggo’s duties, and Dewitt is the only one who understands how to do many of them. Though Dewitt’s body is unable to maintain the alarmed state it entered when he learned of the additional work, he remains stressed out over the weeks that follow. He hopes Viggo will return before he becomes truly overwhelmed. Dewitt is in the RESISTANCE stage of the general adaptation syndrome (GAS).
D) Scientific laws do not account for unseen variations, like wind
Explanation:
Will model in predicting the path of an arrow he was about to shoot failed because scientific laws most times do not account for unseen variations like wind.
Scientific laws are the description of an observed phenomenon in nature.
- Most scientific laws have exceptions.
- Exceptions in scientific laws are conditions in which the law will not hold true.
- There are exceptions to newton's law of motion which Will did not take into account.
learn more:
Newton's law brainly.com/question/11411375
#learnwithBrainly
