Group Members :1.Firdaus 2.Nazhif3.Faiq4.Afiqah

PBL PhysicWhat cause Pak Din

death

TO INVESTIGATE HOW THE PHYSICS PHENOMENA CAUSING THE DEATH OF PAK DIN.

Problem statement

• On 21/3/2014 – Mak Cik Yam went to Tesco to shop for her daughter’s wedding occasion .

• After buying about 400 kg of groceries at the store , Mak Cik Yam asked for a bigger trolley to transport her item to the car.

• On her way to her car, Mak Cik Yam must go down to the escalator.

• At the same time Pak Din just finished buying item he needed. The shop that Pak Cik Din just come out is situated 2 meter from the escalator

• On her way down the escalator , Mak Cik Yam cannot hold down the trolley because it had no magnetize wheels and contain many load.

• At the same time Pak Din had just went out from the store . He was busy checking the item he bought that he did not notice a trolley moving fast toward him.

• The trolley impact him about 2 meter from the escalator . The collision was so great that Pak Din was thrown away and the impact cause him to die .

Synopsis

JUST A COMPARISON PICTURE OF MAK CIK YAM TROLLEY LOAD.

3 K’SKNOW DON’T KNOW NEED TO KNOW

-Load of trolley =400kg-Height of the escalator is 4m-Length of the escalator is 4m-The gradient of the escalator is 5m-The trolley wheel doesn’t have magnet .-Pak Din is 2m from the escalator ,-The surface is frictionless .-Pak Din was thrown backwards during the impact and die.

-Time taken for the trolley to reach Pak Din .-Acceleration of the trolley.-Kinetic Energy and Potential Energy of the trolley.-The velocity of the trolley-The speed of the trolley.-The type of collision .

- Please refer to the mahjong paper.

What are the physical calculation needed to solve the problem :

1. Motion of equation

2. Law of motion

3. Work and energy

4. Momentum & Impulse

Physic Laws Involves

• equations of motion are equations that describe the behaviour of a physical system in terms of its motion as a function of time.

• There are a variety of quantities associated with the motion of objects - displacement (and distance), velocity (and speed), acceleration, and time.

• SUVAT equations:

s = displacement

u = initial velocity

v = final velocity,

a = acceleration

t = time

The Equations Of Motion

• Newton's First Law of Motion:

• Newton's Second Law of Motion:

• Newton's Third Law of Motion:

Laws Of MotionI. Every object in a state of uniform motion tends to remain in that state of

motion unless an external force is applied to it. This we recognize as essentially concept of inertia, and this is often termed simply the "Law of Inertia".

II. The relationship between an object's mass m, its acceleration a, and the applied force F is F = ma. Acceleration and force are vectors (as indicated by their symbols being displayed in slant bold font); in this law the direction of the force vector is the same as the direction of the acceleration vector.

III. For every action there is an equal and opposite reaction.This law is exemplified by what happens if we step off a boat onto the bank of a lake: as we move in the direction of the shore, the boat tends to move in the opposite direction.

• Work EquationMathematically, work can be expressed by the following equation:

W = F • d • cos Θ

F is the force, d is the displacement, and the angle (theta) is defined as the angle between the force and the displacement vector.

The Joule is the unit of work. 1 Joule = 1 Newton * 1 meter

1 J = 1 N * m

Work And Energy

• Gravitational Potential Energy• Gravitational potential energy is the energy stored in an object as the result of its

vertical position or height.

• The energy is stored as the result of the gravitational attraction of the Earth for the object.

PEgrav = mass • g • height

 PEgrav = m *• g • h

• In the above equation, m represents the mass of the object, h represents the height of the object and g represents the gravitational field strength (9.8 N/kg on Earth).

• Kinetic Energy• Kinetic energy is the energy of motion.

• An object that has motion - whether it is vertical or horizontal motion - has kinetic energy.

• The amount of translational kinetic energy that an object has depends upon two variables: the mass (m) of the object and the speed (v) of the object.

• The formula of kinetic energy is the same as potential energy.

• Momentum• Momentum can be defined as "mass in motion.“

• The amount of momentum that an object has is dependent upon two variables: how much stuff is moving and how fast the stuff is moving.

• Momentum depends upon the variables mass and velocity. In terms of an equation, the momentum of an object is equal to the mass of the object times the velocity of the object.

p = m • vwhere m is the mass and v is the velocity.

Momentum and Impulse Connection

Impulse• In physics, the quantity Force • time is known as impulse.

• Since the quantity m•v is the momentum, the quantity m•Δv must be the change in momentum.

F • t = m • ∆v

Impulse = Change in momentum

Collision

• The law of conservation of momentum is not enough to determine the motion of particles after a collision.

• Another property of the motion, kinetic energy, must be known. This is not necessarily conserved.

• If it is conserved, the collision is called an elastic collision; if not, it is an inelastic collision.

Elastic Collision:

Inelastic Collision:

• With the load of the trolley is 400 kg and moving with the final velocity of 7.74 m/s and speed of 1.537 m/s, when it hit Pak Cik Din he was thrown backward and died .

• This shown that load and velocity applied on the trolley can cause Pak Din to die tragically and logically.

Conclusion