Q: The collision in which the relative velocity is zero after collision is

For perfectly inelastic collision\$,e=0\$For perfectly elastic collision\$,e=1\$

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: 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 body \$P\$ moving with a velocity of \$20\$ms\$^{-1}\$ collides with another body \$Q\$ of same mass at rest. After collision \$P\$ comes to rest. What is the velocity of the body \$Q\$ ?

By using momentum conservation,we get,\$m_1u_1+m_2u_2=m_1v_1+m_2v_2\$But \$m_1=m_2=m, u_1=20\$ms\$^{-1}, u_2=0\$ms\$^{-1}, v_1=0\$ms\$^{-1}, v_2=?\$\$ \Rightarrow m \times 20 + m\times 0 = m \times 0 + m\times v_2 \$\$\Rightarrow v_2= 20\$ms\$^{-1}\$.

Question 1

The collision in which the relative velocity is zero after collision is

Accepted Answer

For perfectly inelastic collision$,e=0$For perfectly elastic collision$,e=1$

Question 2

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

Accepted Answer

The potential energy of a body is the energy by virtue of its position or configuration. For example, the heavy ball of a demolition machine is storing energy when it is held at an elevated position. This stored energy due to its position is referred to as potential energy. Similarly, a drawn bow is able to store energy as the result of its change of shape or configuration.

Question 3

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

Accepted Answer

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 $.

Question 4

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

Accepted Answer

$ 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.

Question 5

In a perfectly elastic collision :

Accepted Answer

Elastic collisions occur only if there is no net conversion of kinetic energy into other forms. During the elastic collision, kinetic energy is first converted to potential energy associated with a repulsive force between the particles (when the particles move against this force, i.e. the angle between the force and the relative velocity is obtuse), then this potential energy is converted back to kinetic energy (when the particles move with this force, i.e. the angle between the force and the relative velocity is acute).Also, the average of the momenta before and after the collision is the same. Hence, in a perfectly elastic collision both KE and momentum are conserved.

Question 6

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

Accepted Answer

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

Question 7

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

Accepted Answer

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.

Question 8

Energy equals of a mass of one microgram in kilo joules is

Accepted Answer

GivenEnergy of 1 microgram=?SolutionWe will use Energy mass equivalence$E=mc^{2}$$E=10^{-6}kg\times (3 \times10^{8})^{2}m/s^{2}$$E=9 \times 10^{10}J$Option $A$ is  correct.

Question 9

A body $P$  moving with a velocity of $20$ms$^{-1}$ collides with another body $Q$ of same mass at rest. After collision $P$ comes to rest. What is the velocity of the body $Q$ ?

Accepted Answer

By using momentum conservation,we get,$m_1u_1+m_2u_2=m_1v_1+m_2v_2$But  $m_1=m_2=m,    u_1=20$ms$^{-1},   u_2=0$ms$^{-1},  v_1=0$ms$^{-1},   v_2=?$$ \Rightarrow m \times 20 + m\times 0 = m \times 0 + m\times v_2 $$\Rightarrow  v_2= 20$ms$^{-1}$.

Question 10

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

Accepted Answer

The kinetic energy of a body is the energy by virtue of its motion. This is the definition of kinetic energy. If it has motion then it will have velocity, hence kinetic energy exists.$ K.E = \dfrac{1}{2}mv^2 $

Work Energy And Power

Physics
5103 Views

The collision in which the relative velocity is zero after collision is

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

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

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

In a perfectly elastic collision :

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

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

Energy equals of a mass of one microgram in kilo joules is

A body $P$ moving with a velocity of $20$ ms $^{- 1}$ collides with another body $Q$ of same mass at rest. After collision $P$ comes to rest. What is the velocity of the body $Q$ ?

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

Work Energy And Power

Physics 5103 Views

The collision in which the relative velocity is zero after collision is

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

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

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

In a perfectly elastic collision :

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

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

Energy equals of a mass of one microgram in kilo joules is

A body P moving with a velocity of 20ms−1 collides with another body Q of same mass at rest. After collision P comes to rest. What is the velocity of the body Q ?

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

Physics
5103 Views

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

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

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

A body $P$ moving with a velocity of $20$ ms $^{- 1}$ collides with another body $Q$ of same mass at rest. After collision $P$ comes to rest. What is the velocity of the body $Q$ ?

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