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3 years ago

(answer fast and correctly and i will give you brainiest and 5 star's. )

Physics

2 answers:

oee [108]3 years ago

7 0

Answer:

Energy cannot be created or destroyed.

Explanation:

its in the name, law of "conservation" of energy. energy can only change forms not be destroyed

sattari [20]3 years ago

5 0

Answer: Energy cannot be created or destroyed.

Explanation: The law of conservation of energy states that energy can neither be created nor be destroyed due to energy loss. It can only change its states from one energy state to another.

The efficiency is defined as the ratio of output work to the input work. The efficiency of the fan is not 100%. Because some of the energy is lost in the form of heat and sound. No machine is 100% efficient. There is always some loss of energy takes place.

I really hope this helps and sorry it's late.

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What phenomenon reduces the adverse effects and pressure imposed by solar wind on earth?

inessss [21]

Answer:

The earths magnetic field

Explanation:

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3 years ago

which component of the Star Wars movies is possible according to our current understanding of physics?

Lena [83]

The movie Star Wars is a space opera interstellar epic which uses science and technology in its settings and storylines, although its main focus is not necessarily on science.

Many elements in the films appear to defy simple laws of physics.
One of which is the falling of spaceships when they are hit by a laser beam. Experts said, this is one good example because without gravity in space, ships should travel in the direction of the impact instead of dropping like a stone.

8 0

3 years ago

The initial kinetic energy imparted to a 0.020 kg bullet is 1200 J. (a) Assuming it

Lilit [14]

Answer:

(a) Power= 207.97 kW

(b) Range= 5768.6 meter

Explanation:

Given,

Mass of bullet, $m=0.02 kg$

Kinetic energy imparted, $K=1200 J$

Length of rifle barrel, $d=1 m$

(a)

Let the speed of bullet when it leaves the barrel is $v$ .

Kinetic energy, $K=\frac{1}{2} mv^{2}$

$v=\sqrt{\frac{2K}{m} }$

$=\sqrt{\frac{2\times1200}{0.02} }$

$=346.4m/s$

Initial speed of bullet, $u=0$

The average speed in the barrel, $v_a_v_g=\frac{u+v}{2}$

$=\frac{0+346.4}{2} \\=173.2 m/s$

Time taken by bullet to cross the barrel, $t=\frac{d}{v}$

$=\frac{1}{173.2}\\ =0.00577 second$

Power, $P_a_v_g=\frac{W}{t}$

$=\frac{1200}{0.00577} \\=207.97kW$

(b)

In projectile motion,

Maximum height, $H_m=\frac{v^2\sin^2\theta}{2g} \\$

Range, $R=\frac{v^2\sin2\theta}{g}$

given that, $H_m=R$

then, $\frac{v^2\sin^2\theta}{2g}=\frac{v^2\sin2\theta}{g}\\\sin^2\theta=2\sin\theta\cos\theta\\\\\tan\theta=4\\\theta=\tan^-^14\\\theta=75.96^0\\R=\frac{v^2\sin2\theta}{g}\\=\frac{346.4^2\times\sin(2\times75.96)}{9.8}\\5768.6 meter$

5 0

3 years ago

We can calculate the force that the atmospheric pressure produces on a surface. Consider a living room that has a 4.0m×5.0m floo

qaws [65]

Answer:

Force, $F=2.02\times 10^6\ N$

Explanation:

It is given that,

Length of the room, l = 4 m

breadth of the room, b = 5 m

Height of the room, h = 3 m

Atmospheric pressure, $P=1\ atm=101325\ Pa$

We know that the force acting per unit area is called pressure exerted. Its formula is given by :

$P=\dfrac{F}{A}$

$F=P\times l\times b$

$F=101325\times 4\times 5$

$F=2.02\times 10^6\ N$

So, the total force on the floor due to the air above the surface is $2.02\times 10^6\ N$ . Hence, this is the required solution.

4 0

3 years ago

An object of mass 5 m is lifted to a height of 5 h above the floor. What is the potential energy the object gained in this proce

Gekata [30.6K]

Answer:

Potential energy, E = 25 mgh

Explanation:

Given that,

Mass of the object, m = 5 m

It is lifted to a height of, h = 5 h

It is required to find the potential energy gained by the object. It is given by the product of object's mass, acceleration due to gravity and heigh above ground. It is given by :

$E=m\times g\times h$

$E=5\ m\times g\times 5\ h$

E = 25 mgh

So, the potential energy gained by the object is (25 mgh). Hence, this is the required solution.

7 0

3 years ago