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1 year ago

6

A body of mass 20kg initially at rest is subjected to a force of 40m for 15sec. Calculate the change in k.e

2 answers:

Ede4ka [16]1 year ago

3 0

Explanation:

mass(m)=20kg

velocity(v)=d/t=2.67

k.e=?

now,

k.e=1/2mv^2

=1/2*20*(2.67)^2

=71J

vladimir2022 [97]1 year ago

3 0

Answer:

Explanation:kE =10kg(7.3m²/s²)

=73J

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an electrical generator is an important component in a power plant. which best shows the energy transfer diagram for a generator

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Answer:The answer is B

Explanation:

A generator produces electricity. Energy enters the system (generator) as kinetic energy. It is converted into electrical energy, which can run electrical appliances. Some energy is always wasted as heat and sound. Therefore, Choice B is the best answer.

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2 years ago

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A wire 3.22 m long and 7.32 mm in diameter has a resistance of 11.9 mΩ. A potential difference of 33.7 V is applied between the

Scorpion4ik [409]

Answer:

(a) Current is 2831.93 A

(b) $8.40A/m^2$

(c) $\rho =15.52\times 10^{-9}ohm-m$

Explanation:

Length of wire l = 3.22 m

Diameter of wire d = 7.32 mm = 0.00732 m

Cross sectional area of wire

$A=\pi r^2=3.14\times 0.00366^2=4.20\times 10^{-5}m^2$

Resistance $R=11.9mohm=11.9\times 10^{-3}ohm$

Potential difference V = 33.7 volt

(A) current is equal to

$i=\frac{V}{R}=\frac{33.7}{11.9\times 10^{-3}}=2831.93A$

(B) Current density is equal to

$J=\frac{i}{A}$

$J=\frac{2831.93}{4.20\times 10^{-5}}=8.40A/m^2$

(c) Resistance is equal to

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2 years ago

A SMALL cup of tea has water inside that is very hot, about 80 degrees Celsius. A LARGE bathtub has water inside it that is warm

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2 years ago

A heat engine performs (245 + A) J of work in each cycle while also delivering (142 + B) J of heat to the cold reservoir. Find t

Ganezh [65]

Answer:

The value is $\eta = 54.4 \%$

Explanation:

From the question we are told that

The work input is $W = ( 245 + A ) \ J$

The heat delivered is $Q = (142 + B) \ J$

The value of A is A = 14

The value of B is B = 72

Generally the efficiency of the heat engine is mathematically represented as

$\eta = \frac{W}{Q_t}$

Here $Q_t$ is the total out energy produce by the heat engine and this is mathematically represented as

$Q_t= Q + W$

=> $Q_t= 245 + A + 142 + B$

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So

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2 years ago

Consider the system consisting of the box and the spring, but not Earth. How does the energy of the system when the spring is fu

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Answer:

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Explanation:

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Therefore, the energy when it reaches the ground is equal to the energy when the spring is compressed.

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2 years ago