Rabu, 26 Desember 2012

UAS


Full name : Triana Siska Dewi
Student number : RSA1C311007

Answer:

1. When I still study at senior hight school I often play baseball. Of course when it hit a ball thrown by our friend feels very sick. However, the pain that we feel is related to the kinetic energy possessed by a baseball. Where the kinetic energy is the energy possessed by a moving object whose size is proportional with half the mass multiplied by the square of the velocity.
Ek = ½ m v ^ 2
So when we throw a ball whose mass is greater more than normal with great pace then when we hit the ball it will be more painful.
Try it you compare:
A. Budi throw a baseball a mass of 0.5 kg with a speed of 10m / s.
B. Andi threw baseball's mass 0.5kg with speed 20m / s.

If both balls are about Yudi, which blows more pain felt by Yudi?

Course the ball is thrown by Andi is not it?
Because:
            A. EkA = ½ 0.5 kg (10m / s) ^ 2
                        = 2.5 joules

            B. Ek
B = ½ 0.5 kg (20m / s) ^ 2
                        = 5 joules

Well, from the above events, we can conclude that the greater the kinetic energy possessed by the ball the greater the pain of what when on us.

But how about we throw a ball up that will fall on a hard surface and soft soil or muddy?

2. Kinetic frictional force
Kinetic or dynamic friction force occurs when two objects are moving relative to each other and rubbing each other. In general, obtaining the kinetic frictional force is smaller than the static friction force for the same material. Where the size of the force depends on the friction coefficient of the touch of the two objects.


• Setting up a sled length (x) 1 meter and height (h) 0.5 meter and a stopwatch
• Place a block of wood mass 1kg above sled
• Slowly raise the land up balaok sled gliding and gliding turn when the beams start and stop the stopwatch when the beam reaches the end of the sled
• Measure the length when we picked up the sled to make the beam can slide
• Measure the length of the sled after sled lifted
• Record the time (t) required for the beam to reach the end of the skateboard
• Measure the value of the coefficient of kinetic friction 
 s is length at first = 1 meter
g is gravity = 9,8 m/s^2

3. Strong electric current is the amount of charge that flows in a conductor per unit time, or equal to a strong electric current proportional electrical charge and inversely proportional to the time.
I = q / t
Where:
I = strong electric current (A)
q = electric charge (C)
t = time (s)
 
problems:
 Within 6 minutes a charge of 280 C flows through a conductor. What is the current flowing during those 6 minutes?
Answer:
Given: t = 6 min = 360 second
 
q = 280 C
Asked: I?
I = q / t
= 280 C / 360s
= 0.78 A
So, current flows for 6 minutes at 280 C charge is equal to 0.78 A.

4. Sound is a wave. Sound waves are mechanical waves because they require an intermediary in sound propagation. Where the sound propagation medium can be solid, liquid or gas. Sound wave is a wave in which the propagation lungitudinal, sound waves in the form of density and strain that occurs in a medium consecutive passes.
 Some evidence that the sound is a wave:
1) Can be reflected (reflection)
The sound could be reflected when the sound of the hard surfaces.
For example, our voice will be heard more loudly in the mosque due to the reflection of sound on the mosque walls made of stone and cement.
2) Can be refracted (refiaksi)
Refiaksi  the track of wave is slue direction after passing the boundary between two different media.
For example: we'll hear a sura lightning at night sounds sound louder than thunder in the afternoon this is due to the refraction of the sound waves.
3) Can be bent (diffracted)
Diffraction is flexing event sound waves when passing through a narrow slit.
For example: Andi room and adjacent Budi scream when Andi could hear shouting Budi when recording is different and the room is in a closed state, this is because the sound can pass through a narrow slits.



Ujian Akhir Semester

Full name : Triana Siska Dewi
Student number : RSA1C311007

Answer :
1.
When I still study at senior high school I often play baseball. Of course when it hit a ball thrown by our friend feels very sick. However, the pain that we feel is related to the kinetic energy possessed by a baseball. Where the kinetic energy is the energy possessed by a moving object whose size is proportional with half the mass multiplied by the square of the velocity.
Ek = ½ m v ^ 2
So when we throw a ball whose mass is greater more than normal with great pace then when we hit the ball it will be more painful.
Try it you compare:
A. Budi throw a baseball a mass of 0.5 kg with a speed of 10m / s.
B. Andi threw baseball's mass 0.5kg with speed 20m / s.

If both balls are about Yudi, which blows more pain felt by Yudi?

Course the ball is thrown by Andi is not it?
Because:
            A. EkA = ½ 0.5 kg (10m / s) ^ 2
                        = 2.5 joules

            B. Ek
B = ½ 0.5 kg (20m / s) ^ 2
                        = 5 joule

Well, from the above events, we can conclude that the greater the kinetic energy possessed by the ball the greater the pain of what when on us.

But how about we throw a ball up that will fall on a hard surface and soft soil or muddy?

2.
Kinetic frictional force
Kinetic or dynamic friction force occurs when two objects are moving relative to each other and rubbing each other. In general, obtaining the kinetic frictional force is smaller than the static friction force for the same material. Where the size of the force depends on the friction coefficient of the touch of the two objects.

• Setting up a sled length (x) 1 meter and height (h) 0.5 meter and a stopwatch
• Place a block of wood mass 1kg above sled
• Slowly raise the land up balaok sled gliding and gliding turn when the beams start and stop the stopwatch when the beam reaches the end of the sled
• Measure the length when we picked up the sled to make the beam can slide
• Measure the length of the sled after sled lifted
• Record the time (t) required for the beam to reach the end of the skateboard
• Measure the value of the coefficient of kinetic friction 
 
3.
Strong electric current is the amount of charge that flows in a conductor per unit time, or equal to a strong electric current proportional electrical charge and inversely proportional to the time.
I = q / t
Where:
I = strong electric current (A)
q = electric charge (C)
t = time (s)
 
problems:
 Within 6 minutes a charge of 280 C flows through a conductor. What is the current flowing during those 6 minutes?
Answer:
Given: t = 6 min = 360 second
 
q = 280 C
Asked: I?
I = q / t
= 280 C / 360s
= 0.78 A
So, current flows for 6 minutes at 280 C charge is equal to 0.78 A.

4.
Sound is a wave. Sound waves are mechanical waves because they require an intermediary in sound propagation. Where the sound propagation medium can be solid, liquid or gas. Sound wave is a wave in which the propagation lungitudinal, sound waves in the form of density and strain that occurs in a medium consecutive passes.
 Some evidence that the sound is a wave:
1) Can be reflected (reflection)
The sound could be reflected when the sound of the hard surfaces.
For example, our voice will be heard more loudly in the mosque due to the reflection of sound on the mosque walls made of stone and cement.
2) Can be refracted (refiaksi)
Refiaksi  the track of wave is slue direction after passing the boundary between two different media.
For example: we'll hear a sura lightning at night sounds sound louder than thunder in the afternoon this is due to the refraction of the sound waves.
3) Can be bent (diffracted)
Diffraction is flexing event sound waves when passing through a narrow slit.
For example: Andi room and adjacent Budi scream when Andi could hear shouting Budi when recording is different and the room is in a closed state, this is because the sound can pass through a narrow slits.



Senin, 17 Desember 2012


Based on data from the transport minister lately accidents often occur, either between a car with a car, a motorcycle with a motorcycle, or car with a motorcycle. Of course, a collision between a motorcycle and a car more dangersl than a collision between two motorcycles, assume that the vehicle is moving at the same rate. The mass of the car is much greater than the mass of the motorcycle, so when the car is moving, the momentum of the car is greater than the momentum of the bike motorcycle. When cars and bikes collide or even collide, it is definitely motorcycle bouncing. Because of the greater momentum possessed by an object, the greater the effect caused when the object collision.
where:
 
momentum of an object is defined as the product of the mass of the object with the velocity of the object.
                                                                    (P = m x v)

if mass of car and motorcycle respectively has a mass of 500 kg and 30 kg
moving against one another in a linear trajectory slippery
perfect with v
car: 2 m / s and v motorcycle = - 2 m / s. how the momentum of the car and motorcycle ?
Pcar = m x v
        = 500 kg x 2 m/s
        = 1000 kg m/s

P motorcycle = m x v
                      = 30 kg x -2 m/s
                      = -60 kg m/s
          
then how to change the momentum of the two objects after the collision if the velocity of  motorcycle is +2 m/s  ?

Minggu, 16 Desember 2012

pressure on solids

pressure on solids
 
the greater the force of body weight, the greater the pressure it creates
the smaller the gravity object, the smaller the pressure generated
the smaller the broad field of press, the greater the pressure it creates
greater basal area press, the less pressure caused
so the pressure is directly proportional to the force exerted and inversely with the area to which the force field 


If each block has the same weight, at 27 N, beams Which gives greater emphasis to the floor?
 


discussion:

I beams

A = 30 cm x 10 cm = 300 cm ² = 0.03
F = 27 N
P =  F
       A
P = 27 N   
     0,03
P = 900 Pascal


II beams

A = 20 cm x 10 cm = 200 cm² = 0,02 m²
 P =  F
       A
P = 27 N   
     0,02
P = 1350 Pascal

problems :

A block of mass 300 kg with a sides 20 cm.

Determine the pressure at the base of the beam when the beam is placed on the table at the position as shown in the image above!





Senin, 10 Desember 2012

sumber: http://www.youtube.com/watch?v=mNzh4t504Ag

Creating Simple Magnet



Creating Simple Magnet


You surely already know, what is the magnet? If you do not know or have forgotten, try to open another article about magnet here. Apart from that produced by the natural stone, magnets can also be our own tables. one of them by way of electricity in one direction. Want to know how? Watch carefully the following experiment  ..

The tools you need are:




1. Cables containing copper wires (only if the cord is a duplicate)
2. Spikes (if you can nail a little long)
3. battery
4. Paper clips or other small metallic (tacks, needles, etc.)

How to make it:

1. Peel the skin of copper cable at each end-jung
2. Wrap the copper wire on a nail (try as close as possible)
3. Glue the ends of the copper wires on the battery, and wait a few moments
4. To test it try to hold the nail on the paper clip or other small metal
5. Try to observe what is going on?



How did it happen?

Nails can be like a magnet because there is a process called electromagnetic. In the vicinity of the electric current carrying wire contained magnetic field. In this experiment, the power source is a battery drain flows along copper wires wrapped around the nail. The more loops, the greater / stronger magnetic field. As a result of the existence of this magnetic field, the paper clip / other minor metals can be attached to the nail. Well, now you try to add the number of batteries. Then observe what will happen??

Good luck ...!!