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Vaselesa [24]
3 years ago
6

A rifle of mass M is initially at rest. A bullet of mass m is fired from the rifle with a velocity of v relative to the ground.

What is the expression that gives the velocity of the rifle relative to the ground after the bullet is fired?
Physics
1 answer:
Iteru [2.4K]3 years ago
7 0

Answer:

V_{rifle} = -\frac{mV_{bullet} }{M}.

Explanation:

According to conservation of momentum, the momentum of rifle before fire is equal to the momentum of bullet after fire plus momentum of rifle after fire.

This in mathematics translates to.

(M+m)v_{rifle-before-fire}=Mv_{rifle-after-fire}+mv_{bullet}

rifle is stationary before fire so v_{rifle-before-fire}=0  this means that left side is 0.

0=Mv_{rifle-after-fire}+mv_{bullet}

solving for v_{rifle-after-fire} in above gives us our answer.

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elena-s [515]
Kinetic energy. thermal energy (a low form of energy ) is a form of kinetic energy as it is produced as a result of motion of particles either if they vibrate at their position or they move along longer paths. Motion produces friction or resistance which leads to excitation and thus the heat is produced. The higher the motion of the particles, the higher would be the thermal energy.
7 0
2 years ago
A small metal ball is suspended from the ceiling by a thread of negligible mass. The ball is then set in motion in a horizontal
Gemiola [76]

Answer:

Time taken, T=2\pi \sqrt{\dfrac{l\ cos\theta}{g}}

Explanation:

It is given that, a small metal ball is suspended from the ceiling by a thread of negligible mass. The ball is then set in motion in a horizontal circle so that the thread’s trajectory describes a cone as shown in attached figure.

From the figure,

The sum of forces in y direction is :

T\ cos\theta-mg=0

T=\dfrac{mg}{cos\theta}

Sum of forces in x direction,

T\ sin\theta=\dfrac{mv^2}{r}

mg\ tan\theta=\dfrac{mv^2}{r}.............(1)

Also, r=l\ sin\theta

Equation (1) becomes :

mg\ tan\theta=\dfrac{mv^2}{l\ sin\theta}

v=\sqrt{gl\ tan\theta.sin\theta}...............(2)

Let t is the time taken for the ball to rotate once around the axis. It is given by :

T=\dfrac{2\pi r}{v}

Put the value of T from equation (2) to the above expression:

T=\dfrac{2\pi r}{\sqrt{gl\ tan\theta.sin\theta}}

T=\dfrac{2\pi l\ sin\theta}{\sqrt{gl\ tan\theta.sin\theta}}

On solving above equation :

T=2\pi \sqrt{\dfrac{l\ cos\theta}{g}}

Hence, this is the required solution.

4 0
3 years ago
A force of 8.0 N is along x direction, another force of 6.0 N is along +y direction. If both forces are acting on a point object
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Answer:

Resultant force, R = 10 N

Explanation:

It is given that,

Force acting along +x direction, F_x=8\ N

Force acting along +y direction, F_y=6\ N

Both the forces are acting on a point object located at the origin. Let the resultant force of the object is given by R. So,

R=\sqrt{F_x^2+F_y^2+F_xF_y\ cos\theta}

Here \theta=90^{\circ}

R=\sqrt{F_x^2+F_y^2}

R=\sqrt{8^2+6^2}

R = 10 N

So, the resultant force on the object is 10 N. Hence, this is the required solution.

6 0
3 years ago
What happens if an air conditioner is used in a house that is not well insulated and not well scaled? Explain in terms of energy
stira [4]
It will use a lot more energy (electricity) to cool down the room. Because heat energy from outside the room can easily transfer into the room again if the room is not well insulated. So more energy is needed to cool down the room again
4 0
2 years ago
Scientists often say that light and other forms of electromagnetic radiation have a dual nature
Alex

Answer:

Behaves as a wave.

Explanation:

The dual nature of light means that light behaves as a wave. If the light consisted of small particles, the alternating light and dark bands would not have occurred.

Sometimes it behaves like a particle (called a photon), which explains how light travels in straight lines.

7 0
3 years ago
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