Answer:
13.52 Ω
Explanation:
coefficient of thermal resistance be α
R₀ , R₂₅ , R₉₀ and R₋₃₂ be resistances at 0 , 25 , 90 , and - 32 degree
R₂₅ = R₀ + α x 25
R₉₀ = R₀ + α x 90
R₉₀ - R₂₅ = 65 x α
α = (R₉₀ - R₂₅ )/ 65
= (14.55 - 14) / 65
= .55 / 65 Ω per °C,
R₂₅ = R₀ + α x 25
14 = R₀ + (.55 / 65 )x 25
= R₀ + .2115
R₀ = 13.7885 Ω
R₋₃₂ = R₀ - α x 32
= 13.7885 -( .55 / 65) x 32
= 13.7885 - .27077
= 13.51773 Ω
= 13.52 Ω
78.4 joules is the energy of a 4 kg apple that is sitting on a 2 m high tree branch.
<u>Explanation:
</u>
When an apple falls to the ground from a tree, its positional energy (stored as potential gravitational energy) turns into kinetic energy, during a fall. Chemical potential energy is chemical energy because it is food and potential energy as it can still have ability to move. So, in the given case, kinetic energy is zero.
To find potential energy, the formula would be
Where, given
m – Mass – 4 kg
(Known value)
h – Height - 2 m
Substitute these values, we get
The work done by friction to move the sled is - 1,323 J.
<h3>
What is Coefficient of friction?</h3>
- The friction coefficient is the ratio of the normal force pressing two surfaces together to the frictional force preventing motion between them.
- Typically, it is represented by the Greek letter µ. In terms of math, is equal to F/N, where F stands for frictional force and N for normal force.
- The coefficient of friction has no dimensions because both F and N are measured in units of force (such as newtons or pounds). For both static and kinetic friction, the coefficient of friction has a range of values.
- When an object experiences static friction, the frictional force resists any applied force, causing the object to stay at rest until the static frictional force is removed. The frictional force opposes an object's motion in kinetic friction.
Solution:
Given that
Coefficient of friction (µ) = 0.10
Mass (m) = 90kg
distance covered (d) = 30m
We use the formula:
friction work = -µmgdcos∅
friction work = -0.100 × 90 kg × 9.8 m/s² × 30 m × cos 60°
friction work = - 1,323 J
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The closer to the equator, the hotter the climate will be.
<span>The electromagnetic spectrum is the range of all possible frequencies of electromagnetic radiation. The "electromagnetic spectrum" of an object is the characteristic distribution of electromagnetic radiation emitted or absorbed by that particular object. Hope this helped.</span>
