MOTION

MOTION

It is derived from the Greek word “ Kinema”, meaning “motion”

Dynamics study of the causes of motion.

Kinematics describes the positions & motions of objects in space.

PIONEERS of PHYSICS

GALILEO GALILEI ( 1564 – 1642 )

Studied the motion of free falling bodies.

“All truths are easy to understand once they are discovered; the point is to discover them”.

JOHANNES KEPLER (1571 – 1630)Formulated the laws of planetary motion or the “first laws of nature”

PIONEERS of PHYSICS

ISAAC NEWTON (1642 - 1727)

Formulated the laws of motion as well as the law of universal gravitation.

PIONEERS of PHYSICS

“NO GREAT DISCOVERY WAS EVER MADE W/O A BOLD GUESS”.

“WE LIVE IN A WORLD OF MOTION”

WHAT IS MOTION?

MOTION a change of position or place with reference to a fixed point.

SPEED distance traveled over time.

VELOCITY displacement traveled over time.

HOW FAST OR SLOW OBJECTS OR BODIES MOVE?

CAN YOU CITE EXAMPLES OF SPEED & VELOCITY?

Speed of a school bus is 100kph

Speed/Rate of heartbeat

On a typical day it pumps more than 9,000 liters of blood.

In a typical year it pumps 4.5 million liters of blood.

In a typical lifetime it will beat up to 3,000 million times.

SPEED OF BLOODFLOW

Blood flow is the quantity of blood that passes through the arterial or venous circulation within a period of time and is often expressed in milliliters or liters per minute. (approx. 6-50 liters/minute)

ESCAPE VELOCITY OF PLANET EARTH

To escape the Earth’s gravitational pull, an object must reach an escape velocity of 24,840 miles/hr

VELOCITY OF A CAR RACER

CAN YOU DIFFERENTIATE SPEED & VELOCITY?

Typhoon “Ondoy” is traveling approximately 180 kph heading North. (PAGASA)

Velocity of a typhoon

That there are 25 births per 1000 population in the Phils.

BIRTHRATE OR SPEED OF POPULATION INCREASE

AS OF 2007, PHILIPPINE POPULATION IS APPROX. 87 MILLION

COMPUTING THE SPEED AND VELOCITY OF MOVING BODIES

Speed ( s ) = distance ( d ) time ( t )

Velocity ( v ) = displacement ( d ) time ( t )

Common units: km/hr, m/s, mi/hr, ft/sec

PROBLEMS INVOLVING SPEED AND VELOCITY

1. It only takes 0.5 seconds for a rattlesnake to strike its victim. If you are the “victim” and you are 12.5 meters away from the snake then how fast will the snake reach or strike you?

Speed ( s ) = ?

distance ( d ) = 12.5 meters

time ( t ) = 0.5 seconds

Speed ( s ) = distance ( d ) time ( t )

= 12.5 meters 0.5 second

= 25 meters/sec

Therefore the snake can reach or hit its victim as fast as 25m/s

2. If a private nurse can cover 5 meters from the ICU with a speed of 2.5 m/s then:

(a) How long will it take her to cover the distance? (b) How far will the nurse be from the ICU in 15

seconds?

CAN YOU IDENTIFY THE GIVEN QUANTITIES FROM THE

PROBLEM?

SOLUTION:

a) t = ? t = d/s

t = 5 m = 2 seconds

2.5m/s

Thus, it will only take 2 seconds for the nurse to reach ICU.

b. d = ? d = st

d = ( 2.5m/s )( 15 s )

d = 37.5 meters

Thus, the nurse must have traveled 37.5 meters in 15 seconds.

VELOCITY

PROBLEM 1: Suppose a car traveled 5 miles North East in 0.20 hours then what is the velocity of the car?

PROBLEM 2: Suppose an athlete runs with a velocity of 5 meters/sec Southbound and he is to cover 2 kilometers then:

a.How far will he be in 5 minutes?

b. What velocity is needed to reach the place in 30 minutes?

Exercise on Speed & Velocity

Solve the assigned problem set to you completely:

1. An ambulance travels 60km in 0.6hr. Find the speed of the ambulance.

2. A box of supplies in a hospital is being pulled by John from the main door towards the stock room with a velocity of 1.5m/s. If he covered the distance in 45 seconds then how far is the stock room from the main door?

3. A nurse covered a distance of 20 meters from the nursery to the nurse station in 10 seconds. How fast is he running?

4. A patient in a stretcher is moved by an attendant with a speed of 2m/s, if the emergency room is 200 meters away then in how many minutes will he make it to the ER?

5. An ambulance has to pick up a patient 200 kilometers away from Lourdes Hospital. If he has to be in the patient’s house within 1 hour & 40 minutes then what should be the velocity of the ambulance to reach the place in time?

6. Aldrin moves a patient on a wheelchair from his room to the operating room. If he moves with a velocity of 2 meters/sec and he reached the OR for 1 minute then how far is the OR from the patient’s room?

Set 1: 1 & 4 Set 2: 2 & 5 Set 3: 3 & 6