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patriot [66]
1 year ago
8

A particular electric car is supplied with 300 kJ of chemical energy by the battery. Of this, a total of 70.5 kJ of energy is wa

sted as heat.
Calculate the overall efficiency of the electric car.
Physics
1 answer:
Lorico [155]1 year ago
3 0

Supplied energy=300kJ

  • Wasted energy=70.5J

Used energy:-

\\ \sf\longmapsto 300-70.5=229.5kJ

We know

\boxed{\sf Efficiency=\dfrac{Used\:Energy}{Supplied\:Energy}\times 100}

\\ \sf\longmapsto Efficiency=\dfrac{229.5}{300}\times 100

\\ \sf\longmapsto Efficiency=\dfrac{229.5}{3}

\\ \sf\longmapsto Efficiency=76.5\%

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To hoist himself into a tree, a 72.0-kg man ties one end of a nylon rope around his waist and throws the other end over a branch
sergij07 [2.7K]

Answer:

man upward acceleration is 0.14m/s^2

Explanation:

given data:

mass of man = 72 kg

downward force = 360 N

The mass of man of weight 72 kg is hang from two sections of rope, one section pf rope ties around man waist and other section is ties in man hands. when he pulls down the rope  with 360 N force then each section of  rope pulls with 360 N

we know that

Weight= mass × gravity= 72kg × 9.8 = 705.6N

Force = mass× acceleration

Force= -705.6 + (2 × 358) = 10.4 N

acceleration = \frac{10.4}{72} = 0.14m/s^2

4 0
2 years ago
Un cable está tendido sobre dos postes colocados con una separación de 10 m. A la mitad del cable se cuelga un letrero que provo
lisabon 2012 [21]

Answer:

El peso del cartel es 397,97 N

Explanation:

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La posición del letrero en el cable = En el medio = 5

El ángulo de inclinación del cable a la vertical = tan⁻¹ (0.5 / 5) = 5.71 °

El peso del letrero = La suma del componente vertical de la tensión en cada lado del letrero

El peso del signo = 2000 × sin (5.71 grados) + 2000 × sin (5.71 grados) = 397.97 N

El peso del signo = 397,97 N.

8 0
2 years ago
If a young protostar with a disk is rotating and shrinking. how much faster is it rotating after its size has decreased by a fac
maks197457 [2]
In this system we have the conservation of angular momentum: L₁ = L₂
We can write L = m·r²·ω

Therefore, we will have:
m₁ · r₁² · ω₁ = m₂ · r₂² · ω₂

The mass stays constant, therefore it cancels out, and we can solve for ω<span>₂:
</span>ω₂ =  (r₁/ r₂)² · ω<span>₁
     
Since we know that r</span>₁ = 4r<span>₂, we get:
</span>ω₂ =  (4)² · ω<span>₁
     = 16 </span>· ω<span>₁

Hence, the protostar will be rotating 16 </span><span>times faster.</span>
5 0
2 years ago
According to the article, which pattern of brain waves are most conducive to studying new information?
sashaice [31]
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Hope this helps! :)
7 0
2 years ago
Honeybees can see light in the ________ range of the electromagnetic spectrum.
konstantin123 [22]
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4 0
2 years ago
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