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Work Energy And Power

Q: Two satellites of earth, S_{1} and S_{2} , are moving inthe same orbit. The mass of S_{1} is four times themass of S_{2} . Which one of the following statements is true ?

K.E.=\frac{GMm}{2r}\Rightarrow Kinetic energies are unequal T=\frac{2\pi r^{3/2}}{\sqrt{GM}}\Rightarrow Time period are equal P.E.=-\frac{GMm}{r}\Rightarrow Potential energies are unequal V=\sqrt{\frac{GM}{r}}\Rightarrow Orbital speeds are equal

Q: A lighter body moving with a velocity v collides with a heavier body at rest. Then :

In a collision system where m_1 moves with u_1 initially and m_2 is at rest with m_2 >>> m_1 .Let the final velocity of m_1 be v_1 and m_2 be v_2 .Assumption: Let the collision be elastic. Using linear momentum conservation and equation for coefficient of restitution, m_1u_1 = m_2v_2 + m_1v_1 v_2 - v_1 = u_1 We get v_1 = \dfrac {m_1 - m_2 }{m_1 + m_2} u_1 v_2 = \dfrac {2m_1}{m_1 + m_2} u_1 Using m_2 >>> m_1, we get v_1 = -u_1 and v_2 = 0 .

Q: A spring is stretched up to its maximum length. The spring possesses which of the following forms of energy?

Stretched spring has potential energy stored in it and while released the potential energy will be converted into kinetic energy. Hence, correct answer is option B.

Q: A body at maximum height possesses:

Potential energy is an energy that an object possesses because of its position. So at the highest position, its potential energy is maximum.

Q: The K.E. of a body can be increased maximum by doubling its:

K.E = \dfrac{1}{2}mv^2 K.E \propto m & K.E \propto v^2 So doubling mass will double the kinetic energy and doubling speed will make kinetic energy 4 times. \therefore The K.E. of a body can be increased maximum by doubling its speed.

Q: A ball of mass M moving with a velocity V collides head on elastically with another of same mass but moving with a velocity v in the opposite direction. After collision,

Using conservation of linear momentum we have: M_1u_1-M_2u_2=-M_1v_1+M_2v_2 MV-Mu_2=-Mv+Mv_2 V-u_2=-v+v_2 .............(i)and as for a perfect elastic collision we have e=1 , thus we get v_2+v=u_2+V .................(ii)Using these two equations we get: u_2=v and v_2=V Thus, the velocities are exchanged between the two balls.

Q: Name the type of energy (kinetic energy K or potential energy U ) possessed in a compressed spring:

When you compress a spring, it possess potential energy. The force of compression is proportional to the compression, according to Hooke's Law. Releasing the spring turns the potential energy into kinetic energy. The spring can be then used to propel some object.

Q: In SI system, the unit of P.E. is :

In SI unit energy is measured in Joules.Therefore, S.I unit of potential energy is Joule(J).

Physics
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JEE Mains JEE Advanced AIIMS BITSAT Easy Qs Med Qs Hard Qs

Two satellites of earth, $S_{1}$ and $S_{2}$ , are moving in
the same orbit. The mass of $S_{1}$ is four times the
mass of $S_{2}$ . Which one of the following statements is true ?

The kinetic energies of the two satellites are

equal

The time period of

S_{1}

is four times that of

S_{2}

The potential energies of earth and satellite in

the two cases are equal

S_{1}

and

S_{2}

are moving with the same speed

Easy

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A lighter body moving with a velocity $v$ collides with a heavier body at rest. Then :

the lighter body rebounces with twice the velocity of bigger body

the lighter body retraces its path with the same velocity in magnitude

the heavier body does not move practically

both (2) and (3)

Easy

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A spring is stretched up to its maximum length. The spring possesses which of the following forms of energy?

Kinetic energy

Elastic potential energy

Electric energy

Magnetic energy

Easy

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A body at maximum height possesses:

Kinetic energy

Potential energy

Solar energy

Heat energy

Easy

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Complete the following sentence:
The potential energy of a body is the energy by virtue of its _______ .

motion

position

Both A and B

None of these

Easy

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The K.E. of a body can be increased maximum by doubling its:

mass

weight

speed

density

Easy

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Complete the following sentence:
The kinetic energy of a body is the energy by virtue of its______ .

force

motion

roughness

all the above

Easy

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A ball of mass M moving with a velocity V collides head on elastically with another of same mass but moving with a velocity v in the opposite direction. After collision,

the velocities are exchanged between the two balls

both the balls come to rest

both of them move at right angles to the original line of motion

one ball comes to rest and another ball travels back with velocity 2V

Easy

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Name the type of energy (kinetic energy $K$ or potential energy $U$ ) possessed in a compressed spring:

U

K

Both

U

and

K

None

Easy

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In SI system, the unit of P.E. is :

erg

dyne-cm

joule

none of these

Easy

View Solution

Work Energy And Power

Physics 190 Views

Two satellites of earth, S1​ and S2​, are moving in the same orbit. The mass of S1​ is four times the mass of S2​. Which one of the following statements is true ?

A lighter body moving with a velocity v collides with a heavier body at rest. Then :

A spring is stretched up to its maximum length. The spring possesses which of the following forms of energy?

A body at maximum height possesses:

Complete the following sentence:The potential energy of a body is the energy by virtue of its _______ .

The K.E. of a body can be increased maximum by doubling its:

Complete the following sentence: The kinetic energy of a body is the energy by virtue of its______ .

A ball of mass M moving with a velocity V collides head on elastically with another of same mass but moving with a velocity v in the opposite direction. After collision,

Name the type of energy (kinetic energy K or potential energy U) possessed in a compressed spring:

In SI system, the unit of P.E. is :

Physics
190 Views

Two satellites of earth, $S_{1}$ and $S_{2}$ , are moving in
the same orbit. The mass of $S_{1}$ is four times the
mass of $S_{2}$ . Which one of the following statements is true ?

A lighter body moving with a velocity $v$ collides with a heavier body at rest. Then :

Complete the following sentence:
The potential energy of a body is the energy by virtue of its _______ .

Complete the following sentence:
The kinetic energy of a body is the energy by virtue of its______ .

Name the type of energy (kinetic energy $K$ or potential energy $U$ ) possessed in a compressed spring: