Answer:
Answered
Explanation:
A) The work done by gravity is zero because displacement and the gravitational force are perpendicular to each other.
W= FS cosθ
θ= 90 ⇒cos90 = 0 ⇒W= 0
B) work done by tension
W= Tcosθ×S= 5cos30×2.30= 10J
C) Work done by friction force
W= f×s=1×2.30= 2.30 J
D) Work done by normal force is Zero because the displacement and the normal force are perpendicular to each other.
E) The net work done= Work done by tension in the rope - frictional work
=10-2.30= 7.7 J
You should select Choice-4 .
The height to which the weight-watcher must climb to work off the equivalent 991 (food) Calories is 0.59 Km
<h3>How to determine the energy. </h3>
1 food calorie = 103 calories
Therefore,
991 food calories = 991 × 103
991 food calories = 102073 calories
Multiply by 4.2 to express in joule (J)
991 food calories = 102073 × 4.2
991 food calories = 428706.6 J
<h3>How to determine the height </h3>
- Energy (E) = 428706.6 J
- Mass (m) = 73.9 kg
- Acceleration due to gravity (g) = 9.8 m/s²
E = mgh
Divide both side by mg
h = E / mg
h = 428706.6 / (73.9 × 9.8)
h = 591.95 m
Divide by 1000 to express in km
h = 591.95 / 1000
h = 0.59 Km
Learn more about energy:
brainly.com/question/10703928
Answer:
No.
Explanation:
The "guide to Engineering and land surveying" for professional engineers and land surveyors by the California board reviews that an unlicensed person cannot be a sole owner of an engineering business, unless there is partnership with a licensed engineer.
Answer:
5 × 10¹⁰ or 5 billion times louder is the intensity of sound at a rock concert in comparison with that of a whisper
Explanation:
Given that at a rock concert;
the intensity of sound is 110 dB compared to a whisper of 3 dB
Now; how many times louder will that of the whisper be compared to the sound of the rock concert
Using the formula for calculating decibels (dB);
For 110 dB
dB = 10log₁₀(W)
110 dB = 
110 dB = 10¹¹
For 3dB
dB = 10log₁₀(W)
3 dB = 
3 dB = 2
Now:
(110/3)dB = 10¹¹/2
(110/3)dB = 5 × 10¹⁰ or 5 billion times louder is the intensity of sound at a rock concert in comparison with that of a whisper
