ENRICHMENT ACTIVITY

ENRICHMENT ACTIVITY

By Ma. Majella Nieva

Open Ended

What does conservation of momentum imply?

Multiple Choice

HOW CAN YOU DIFFERENTIATE ELASTIC COLLISIONS FROM INELASTIC COLLISIONS?

• Elastic Collisions are collisions where a deformation of the object is observed after collision, while Inelastic Collisions are collisions where the objects keep their oriiginal shape after colliding.

• Elastic Collisions are collisions where the total momentum and the kinetic energy of the system are conserved. Inelastic Collisions on the other hand are collisions where only the total momentum of the system is conserved after the collision.

• Elastic Collisions are collisions where only the total momentum of the system is conserved. Inelastic Collisions on the other hand are collisions where both the total momentum of the system and it kinetic energy are conserved after collision.

• Elastic Collisions are collisions where two objects stick together after the collision while Inelastic Collisions are collisions where the objects bounced off from one another after collision.

Multiple Select

Which among the following shows elastic (imperfect) collisions?

• Collision beween bumper cars in an arcade.

• A ball for basketball and volleyball collided with each other.

• One truck pushes the car being stuck underneath after hitting it.

• A car which have its front part deformed after hitting another car.

• Hitting the empty can with the slipper when playing "Tumbang Preso".

Both the total momentum and the kinetic energy of the system are conserved after the collision.

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• Collision beween bumper cars in an arcade.

• A ball for basketball and volleyball collided with each other.

• Hitting the empty can with the slipper when playing "Tumbang Preso".​

​Elastic Collisions

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Open Ended

Which among the following shows inelastic (imperfect) collisions?

A. Collision beween bumper cars in an arcade.

B. A ball for basketball and volleyball collided with each other.

C. One truck pushes the car being stuck underneath after hitting it.

E. A car which have its front part deformed after hitting another car.

F. Hitting the empty can with the slipper when playing "Tumbang Preso".

G. Celestial objects (particularly asteroids) colliding and becomes one mass.

Only the total momentum is conserved.

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The kinetic energy of the system is converted into another form of energy or being converted into work by crumpling or deforming of the object after collision. ​

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• One truck pushes the car being stuck underneath after hitting it.

• A car which have its front part deformed after hitting another car.

• Celestial objects (particularly asteroids) colliding and becomes one mass.

​Inelastic Collisions

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​​Conservation of Momentum in Elastic Collisions

​​Conservation of Momentum in Inelastic Collisions

​​Conservation of Momentum in In Objects that Breaks Apart

CONSERVATION OF MOMENTUM:

Σp_before = Σp_after | p₁ + p₂ = p₁' + p₂'

Draw

A 0.060-kg tennis ball, moving with a speed of 5.50 m/s, has a head-on collision with a 0.090-kg ball initially moving in the same direction at a speed of 3.00 m/s Assuming a perfectly elastic collision, determine the speed and direction of the tennis ball after the collision if the resulting velocity of the other ball after the collision is 4.60 m/s.

Given: m₁ = 0.060-kg ball | v₁ = 5.50 m/s | m₂ = 0.090-kg ball | v₂ = 3.00 m/s

| v₂^' = 4.60 m/s.

Unknown: v₁^' = ?

Formula: m₁v₁ + m₂v₂ = m₁v₁’ + m₂v₂’

Solution:

(0.060 kg)(5.50 m/s) + (0.090 kg)(3.00m/s) = (0.060 kg)(v₁') + (0.090kg)(4.60m/s)

0.33 kg.m/s + 0.27 kg.m/s = (0.060 kg)(v₁') + 0.414 kg.m/s

0.60 kg.m/s = (0.060 kg)(v₁') + 0.414 kg.m/s

(-0.414 kg.m/s) + 0.60 kg.m/s = (0.060 kg)(v₁') + 0.414 kg.m/s - 0.414 kg.m/s​

0.186 kg.m/s / 0.060 kg = (0.060 kg)(v₁') / 0.060 kg

3.1 m/s = v₁'​

Answer: The speed of the tennis ball after the collision is 3.1 m/s and its moving in the same direction as other ball.

ENRICHMENT ACTIVITY: Lesson 22

By Ma. Majella Nieva

Fill in the Blank

Mechanical energy is a form of energy which an object possess due to its ________ or ________.

Multiple Choice

(I) Kinetic Energy is a form of mechanical energy that an object possess due to its position while (II) potential energy is a form of mechanical energy that an object possess when it is moving.

• I and II are true

• I is true. II is false

• I is false. II is true.

• I and II are false.

Multiple Select

Which among the following are examples of / shows potential energy?

• Fast flowing flood

• A rubber band being stretched.

• A rock moving downward the hill.

• A kid playing his/her hoverboard.

• Sitting on the top part of the slide before sliding down

• Energy that is stored in an object due to its position relative to some zero position.

B. A chandelier hanging.

C. A rubber band being stretched.

F. Sitting on the top part of the slide before sliding down.

POTENTIAL ENERGY​

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Multiple Select

Which among the following are examples of / shows kinetic energy?

• Fast flowing flood

• A rubber band being stretched.

• A rock moving downward the hill.

• A kid playing his/her hoverboard.

• Sitting on the top part of the slide before sliding down

• Energy an object has because of its motion

• Energy in MOTION​

A. Fast flowing flood

D. A rock moving downward the hill.

E. A kid playing his/her hoverboard.

KINETIC ENERGY​

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Fill in the Blank

The conservation of mechanical energy points out that the total mechanical energy of an isolated system is conserved. Given this and looking at the diagram provided, the total mechanical energy present on the pendulum as it completes its cycle remains _________.

Fill in the Blank

Following the previous concept, conservation of momentum it is observed that as the kinetic energy _______, its potential energy ________ and vice versa.

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Multiple Select

At which point(s) does the pendulum bob have its highest possible KE?

Multiple Select

At which point(s) does the pendulum bob have its highest possible PE?

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​KINETIC ENERGY

K.E. = ½ (mv2 )

Where:

• KE – kinetic energy (kg.m²/s² or J) 

• m – mass (kg) 

• v – velocity (m/s)

POTENTIAL KINETIC ENERGY

G.P.E. = mgh 

Where:

• GPE – gravitational potential energy (kg.m²/s² or J) 

• m – mass (kg) 

• h – height (m)

• g – acceleration due to gravity (9.8 ms²)

TOTAL MECHANICAL ENERGY

TME = KE + PE

Draw

A novice skier that has a mass of 59 kg, starting from rest, slides down an icy frictionless incline whose vertical height is 105 m. What is the potential energy of the skier at the top of the incline? (g = 9.8 m/s²)

Given: m = 59 kg | h = 105 m | g = 9.8 m/s²

Unknown: PGE = ?

Formula: PGE = mgh

Solution:

PGE = mgh

PGE = (59 kg) (9.8 m/s²)(105 m)

PGE = 60,711 kg. m²/s²​

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Answer: The potential energy of the skier at the top of the incline is 60,711 kg. m²/s² or 60,711 J

Draw

A novice skier that has a mass of 59 kg, starting from rest, slides down an icy frictionless incline whose vertical height is 105 m. What is the total mechanical energy of the skier at the top of the incline?

Given: m = 59 kg | h = 105 m | g = 9.8 m/s² | PGE = 60,711 kg. m²/s²

we assume that the KE of the skier at the top is 0 J​

Unknown: TME = ?

Formula: TME = KE + PE

Solution:

TME = KE + PE

TME = 0 J + 60,711 J

TME = 60, 711 J​

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Answer: The total mechanical energy of the skier at the top of the incline is 60, 711 J

Draw

A novice skier, starting from rest, slides down an icy frictionless incline whose vertical height is 105 m. What is the kinetic energy of the skier when s/he reaches the ground or surface? (Assuming that all potential energy are converted to kinetic energy)

Given: m = 59 kg | h = 105 m | g = 9.8 m/s² | PGE = 60,711 kg. m²/s²

we assume that the PE became 0 J​

Unknown: KE of the skier right before she reached the surface

Formula: TME = KE + PE

Solution:

TME = KE + PE

KE = TME - PE

KE = 60,711 J + 0 J

KE= 60, 711 J​

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Answer: The kinetic energy of the skier before she reached the surface is 60, 711 J

Draw

A novice skier, starting from rest, slides down an icy frictionless incline whose vertical height is 105 m. How fast is s/he going right before she reaches the bottom?

Given: m = 59 kg | h = 105 m | g = 9.8 m/s² | KE= 60, 711 J

we assume that the PE became 0 J​

Unknown: v of the skier as it reaches the surface

Formula: TME = KE + PE

Solution:

TME = KE + PE

KE = TME - PE

KE = 60,711 J + 0 J

KE= 60, 711 J​

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Answer: The kinetic energy of the skier before she reached the surface is 60, 711 J