Tag: renewable and non-renewable resources

Questions Related to renewable and non-renewable resources

A body of mass $15\ kg$ is raised from certain depth. If the work done in raising it by $10m$ is $1620J$, its velocity at this position is$(g=10 { ms }^{ -2 })$:

physics types of energy renewable and non-renewable resources renewable and non-renewable sources of energy substances, objects and energy

  1. ${ 2\ ms }^{ -1 }$

  2. ${ 4\ ms }^{ -1 }$

  3. ${ 1\ ms }^{ -1 }$

  4. ${ 8\ ms }^{ -1 }$

Show answer
Correct Option: B
Explanation:

work done=PE+KE

$1620=mgh+\dfrac{mv^2}{2}$
$1620=15\times 10\times 10+\dfrac{15v^2}{2}=1500+\dfrac{15v^2}{2}$
$v=4m/s$

A body of mass 5 kg falls from a height of
30 metre. If its all mechanical energy is changed into heat, then heat produced
will be:-

physics types of energy renewable and non-renewable resources renewable and non-renewable sources of energy substances, objects and energy

  1. 350cal

  2. 150 cal

  3. 60cal

  4. 6cal

Show answer
Correct Option: A
Explanation:
work done $=mgn$
$= 5 \times 9.8 \times 30 = 14705$
Heat produce $=\dfrac{1470}{4.2}= \boxed{350\ cal}$
$\boxed {Answer\ is\ A}$



























The conservation principle of mechanical energy requires that

physics types of energy renewable and non-renewable resources renewable and non-renewable sources of energy substances, objects and energy

  1. The acceleration should be zero

  2. There should be no external forces

  3. The motion should be restricted to the gravitational force

  4. The force should be conservative

Show answer
Correct Option: B

Mechanical Energy is conserved under

physics types of energy renewable and non-renewable resources renewable and non-renewable sources of energy substances, objects and energy

  1. Conservative system of forces

  2. disipative forces

  3. (A) and (B)

  4. none of these

Show answer
Correct Option: C

A mass of $0.5$ kg is suspended from wire, then lemgth of wire increase by $3$ mm then find out work done:

physics types of energy renewable and non-renewable resources renewable and non-renewable sources of energy substances, objects and energy

  1. $4.5 \times {10^{ - 3}}J$

  2. $7.3 \times {10^{ - 3}}J$

  3. $9.3 \times {10^{ - 2}}J$

  4. $2.5 \times {10^{ - 2}}J$

Show answer
Correct Option: A

The work done by all the forces (external and internal) on a system equals the change in 

physics types of energy renewable and non-renewable resources renewable and non-renewable sources of energy substances, objects and energy

  1. Total energy

  2. Kinetic energy

  3. Potential energy

  4. none of these

Show answer
Correct Option: B,C

In a hydroelectric power plant ___ energy is converted into ____ energy.

physics types of energy renewable and non-renewable resources renewable and non-renewable sources of energy substances, objects and energy

  1. Chemical into electrical

  2. Chemical into mechanical

  3. Mechanical into electrical

  4. Electrical into mechanical

Show answer
Correct Option: C
Explanation:

In hydroelectric power plant following sequence of energy transformation take place, 

Kinetic energy of water to potential energy of water to mechanical energy of turbine to electric energy through generator.
So among the options given best possible answer is option C.

A single conservative force F(x) acts on a $1$ kg particle that moves along the x-axis. The potential energy U(x) is given by $U(x) = 10+(x-1)^2$ Where x is in meters. At x =$2$ m, the particle has a kinetic energy of $8$ Joules. Then the mechanical energy of particle is

physics types of energy renewable and non-renewable resources renewable and non-renewable sources of energy substances, objects and energy

  1. $18$ J

  2. $19$ J

  3. $20$ J

  4. $10$ J

Show answer
Correct Option: A

If $484J$ of energy is spent in increasing the speed of a wheel from $60rpm$ to $360\ rpm$, the $M.I$ of the wheel is

physics types of energy renewable and non-renewable resources renewable and non-renewable sources of energy substances, objects and energy

  1. $1.6\ kg\ m^{2}$

  2. $0.3\ kg\ m^{2}$

  3. $0.7\ kg\ m^{2}$

  4. $1.2\ kg\ m^{2}$

Show answer
Correct Option: C
Explanation:

$\begin{array}{l} { \eta _{ 1 } }=60rpm=\dfrac { { 60 } }{ { 60 } } rps=1rps \ \therefore { w _{ 1 } }=2r{ \eta _{ 1 } }=2\pi  \ { \eta _{ 2 } }=\dfrac { { 360 } }{ { 60 } } rpm=6rps \ { w _{ 2 } }=2\pi { \eta _{ 2 } }=12\pi  \end{array}$

484 joule of energy is spent in increasing.
$\begin{array}{l} \frac { 1 }{ 2 } Iw _{ 2 }^{ 2 }-\dfrac { 1 }{ 2 } Iw _{ 1 }^{ 2 }=484 \ \dfrac { I }{ 2 } \left( { { w _{ 2 } }+{ w _{ 1 } } } \right) \left( { { w _{ 2 } }-{ w _{ 1 } } } \right) =484 \ \dfrac { I }{ 2 } \left( { 12\pi +2\pi  } \right) \left( { 12\pi -2\pi  } \right) =484 \ I\, \, 14\pi .10\pi =484 \ I=\dfrac { { 484\times 2 } }{ { 140\times { \pi ^{ 2 } } } } =\dfrac { { 484\times 2 } }{ { 140\times 9.86 } }  \ =0.7\, \, kg\, \, { m^{ 2 } } \end{array}$
Option C.

State True or False :
Coal forms from plants. 

physics sources of energy renewable and non-renewable resources renewable and non-renewable sources of energy substances, objects and energy

  1. True

  2. False

Show answer
Correct Option: A
Explanation:

Coal is fossil fuel formed from remains of plants that lived and died millions of years ago.