Question

Answer this question in simple words:

Answer 1

Answer:

The basic concept to apply in all the parts of the question is that :

$\boxed{ \sf{ \orange{ \small{Conservation \: Of \: Mechanical \: Energy \: }}}}$

1) Position B is the extreme position. Hence it has stopped and has no Velocity.

Thus the Bob has only Potential energy and no Kinetic energy.

PE = mgh = 0.2 × 10 × 5 = 10 J

So the total Mechanical Energy

= PE + KE

= 10 + 0

= 10 J

2) Since total Mechanical Energy remains constant , it will be 10 J even at point C

3) Potential energy at Point A is zero. Let Velocity at that point be v

∴ PE1 + KE1 = PE2 + KE2

=> 10 + 0 = 0 + ½mv²

=> ½mv² = 10

=> mv² = 20

=> 0.2 v² = 20

=> v² = 20/0.2 = 100

=> v = 10 m/s.

Answer 2

$\huge\star\mathfrak\blue{{Answer:-}}$

The basic concept to apply in all the parts of the question is that :

\boxed{ \sf{ \orange{ \small{Conservation \: Of \: Mechanical \: Energy \: }}}}

1) Position B is the extreme position. Hence it has stopped and has no Velocity.

Thus the Bob has only Potential energy and no Kinetic energy.

PE = mgh = 0.2 × 10 × 5 = 10 J

So the total Mechanical Energy

= PE + KE

= 10 + 0

= 10 J

2) Since total Mechanical Energy remains constant , it will be 10 J even at point C

3) Potential energy at Point A is zero. Let Velocity at that point be v

∴ PE1 + KE1 = PE2 + KE2

=> 10 + 0 = 0 + ½mv²

=> ½mv² = 10

=> mv² = 20

=> 0.2 v² = 20

=> v² = 20/0.2 = 100

=> v = 10 m/s.