newton

1. Newton's Laws
SUBTOPIC: Demonstration of Newton's Three Laws of Motion and the Law of Gravitation
OBJECTIVES:
The students will:
1) give examples of each of Newton's Three laws as they occur in everyday experiences
2) visualize and differentiate the difference between a direct proportion and an inverse
proportion using the formula F=ma
Background Information
Isaac Newton summed up motion in three laws. Today we take these laws for granted as we
grow up assuming they are true. We do not realize the struggles scientists went through in
attempt to understand the world around them. The following activities use brainstorming,
discussion, and simple labs to illustrate the laws.
Newton's Three Laws:
1) An object which is moving at a constant velocity or at a state of rest does not change its state
unless a force acts upon it.
2) Acceleration of an object increases as the amount of force causing the acceleration increases
when mass is constant.
3) For every force, there is an equal and opposite force
Isaac Newton menyimpulkan gerakdalamtigahukum.Hari ini kitamengambil hukum-hukumuntuk
diberikan denganasumsi merekabenar.Kami tidakmenyadari perjuangan parailmuwan pergi melalui
dalamupaya untukmemahami duniadi sekitarmereka.Kegiatanberikutmenggunakan tukarpendapat,
diskusi,danlaboratorium sederhanauntukmenggambarkan hukum.
NewtonTigaHukum:
1) Sebuahobjek yangbergerakdengan kecepatankonstan ataukeadaandiamtidakmengubah keadaan
kecuali kekuatanbertindak atasnya.
2) Percepatan suatubendameningkatsebagai jumlahgayayangmenyebabkan peningkatan akselerasi
ketikamassaadalahkonstan.
3) Untuk setiap gaya,ada gaya yang samadan berlawanan

2. ACTIVITY #1:
Newton's First Law
20 min
MATERIALS: CHALK AND BLACKBOARD
PROCEDURE:
1) Brainstorm everyday examples of the first law.
2) Present a lecture to students, including the following necessary background information:
Just prior to Newton's time Galileo had worked with the idea of acceleration. Galileo could only
guess about time since precise clocks had not been invented. This is why he rolled metal balls
down smooth ramps. Since he noticed how a ball slowed when rolling across the floor, he
concluded that friction was the cause. Thus friction was responsible for the idea that objects in
motion naturally come to rest. But 'rest' is just one kind of constant velocity. The concept of
inertia and Newton's 1st law emerged from this insight.
3) Use some of the following examples to explain to the students how Newton's first law occurs
in everyday events:
a) car suddenly stops and you strain against the seat belt
b) when riding a horse, the horse suddenly stops and you fly over its head
c) the magician pulls the tablecloth out from under a table full of dishes
d) the difficulty of pushing a dead car
e) lawn bowling on a cut and rolled lawn verses an uncut lawn
f) car turns left and you appear to slide to the right
1.Brainstorming contoh sehari-hari hukum pertama.
2) Menyajikan kuliah kepada mahasiswa, termasuk informasi latar belakang yang diperlukan
berikut:
sebelum waktu Newton Galileo telah bekerja dengan ide percepatan. Galileo hanya bisa
menebak tentang waktu sejak jam yang tepat belum ditemukan. Inilah sebabnya mengapa ia
berguling bola logam turun landai halus. Karena ia melihat bagaimana bola melambat ketika
bergulir di lantai, ia menyimpulkan bahwa gesekan adalah penyebabnya. Jadi gesekan
bertanggung jawab atas gagasan bahwa benda bergerak secara alami akan kena. Tapi 'istirahat'
adalah salah satu jenis kecepatan konstan. Konsep inersia dan hukum 1 Newton muncul dari
wawasan ini.

3. 3) Gunakan beberapa contoh berikut untuk menjelaskan kepada siswa bagaimana hukum
pertama Newton terjadi pada peristiwa sehari-hari:
a) mobil tiba-tiba berhenti dan Anda saring terhadap sabuk pengaman
b) ketika menunggang kuda, kuda tiba-tiba berhenti dan Anda terbang di atas kepala
c) si penyihir menarik taplak meja dari bawah meja yang penuh dengan piring
d) kesulitan mendorong mobil mati
e) bowling rumput pada luka dan berguling rumput ayat sebuah rumput dipotong
f) mobil belok kiri dan Anda tampaknya geser ke kanan
ACTIVITY #2:
Constant Force Increases Speed
25 minutes
MATERIALS: SKATEBOARD AND SPRING SCALE
PROCEDURE:
1) Have a student bring in a skateboard.
2) Have one student stand on the skateboard at the front of the class and hold one end of the
spring scale.
3) Another student should pull the first student at a constant force of 10 newtons.
4) Observe the speed of the students as they keep the force constant.
5) Explain that this shows the direct relationship between force and acceleration.
1. siswa membawa skateboard
2. salah satu siswa berdiri pada skateboard di depan kelas dan memegang spring scale di ujung
3. siswa lain menarik siswa yang pertama padagaya konstan sebesar 10 newton
4. amati kecepatan siswa karena gaya yang konstan
5. menjelaskan bahwa ini menunjukkan hubungan antara gaya dan percepatan

4. ACTIVITY #3:
Newton's Third Law
10 minutes
MATERIALS: CHALK AND BLACKBOARD
PROCEDURE:
1) Brainstorm everyday examples of the third law with the class. Listed below are some
examples:
a) rockets leaving earth--many physicists of the nineteen hundreds (Goddard's time) said that
rockets could never leave the earth. Discuss how a spaceship flies in space.
b) guns being fired- discuss why they kick in proportion to the size of the bullet. Why is the
stock of the rifle so large? What would happen if the stock of a shotgun came back to a point
shape?
c) two cars hit head on
d) astronauts in space
e) pool or billiards
f) jumping out of a boat onto the dock
1) Diskusikan contoh sehari-hari hukum ketiga dengan kelas. Di bawah ini adalah beberapa
contoh:
a) roket meninggalkan bumi - banyak fisikawan dari sembilan belas ratusan (waktu Goddard)
mengatakan bahwa roket tidak bisa meninggalkan bumi. Diskusikan bagaimana sebuah pesawat
ruang angkasa terbang di angkasa.
b) menembak dengan senjata- membahas perbandingan sentakan dengan ukuran peluru.
Mengapa stok senapan begitu besar? Apa yang akan terjadi jika stok senapan kembali?
Pada senapan ,peluru mendorong senapan kebelakang(aksi). sebagai reaksi, senapan mendorong
peluru kedepan sehingga senapan akan terdorong kebelakang
c) dua mobil menabrak
d) astronot di ruang angkasa
e) kolam renang atau biliar
f) melompat dari perahu ke dermaga

5. ACTIVITY #5:
Balloon Races
50 minutes
MATERIALS: 3 LONG BALLOONS, 1 PLASTIC STRAW, 60 CM (OR MORE) OF
FINE WIRE OR FISHING LINE, TAPE, MODEL AIRPLANE (BALSA WOOD),
MARKER
PROCEDURE:
1) Have the students follow the procedures listed below:
a) Blow up balloons, fasten them with rubber bands, and label them A, B, and C.
b) Tape the straw lengthwise to Balloon B and run the wire through the straw.
c) Tape Balloon C to the top of the fuselage of the model airplane, placing the balloon opening
toward the tail of the airplane.
d) Loosen the rubber band on Balloon A very slowly and record the speed and direction of
movement.
e) Now, on Balloon B, have a partner hold each end of the wire through the straw and keep the
wire tight.
Cut the rubber band quickly and observe the balloon. Record observations.
f) Draw a sketch showing the direction the air in the balloon moved. Also, on the same sketch,
draw a diagram of how the balloon moved along the wire.
g) To test Balloon C, have a partner hold the airplane loosely. Cut the rubber band as your
partner releases the airplane. Record the flight. You may wish to stage olympic type
competitions between lab partners.
Hint: Try different shapes of balloons. Elongated should work the best. Also a round trip rocket
could be designed.
2) Have the students answer the following questions:
a) Describe the reaction of the rubber band when it was cut.
b) Describe the flight of Balloon B.
c) What was the force that moved the Balloon B?

6. d) Why did Balloon B move differently from Balloon A?
e) Why did Balloon B and Balloon C move more rapidly than Balloon A?
f) State Newton's third law and explain how this activity illustrates it.
1) Mintalah siswa mengikuti prosedur di bawah ini:
a) Meniup balon, kencangkan dengan karet gelang, dan beri label mereka A, B, dan C.
b) Ambil sedotan masukan ke Balloon B dan kawat melalui sedotan.
c) Balloon C ke atas badan pesawat model pesawat terbang, menempatkan pembukaan balon ke
arah ekor pesawat.
d) Kendurkan karet gelang di Balloon A sangat lambat dan mencatat kecepatan dan arah
gerakan.
e) Sekarang, pada Balloon B, dua orang memegang masing-masing ujung kawat melalui sedotan
dan menjaga kawat diregangkan.
Potong pita karet dengan cepat dan mengamati balon. Catat Pengamatan.
f) Buatlah sketsa yang menunjukkan arah udara balon bergerak. Juga, pada sketsa yang sama,
menggambar diagram tentang bagaimana balon bergerak sepanjang kawat
g) Untuk menguji Balloon C, teman memegang pesawat . Potong pita karet lalu pasangan Anda
akan melepaskan pesawat. Catat penerbangan.
2) Mintalah siswa menjawab pertanyaan-pertanyaan berikut:
a) Jelaskan reaksi karet gelang ketika itu dipotong.
b) Jelaskan penerbangan dari Balloon B.
c) Apa kekuatan yang menggerakkan Balloon B?
d) Mengapa Balon B bergerak berbeda dari Balloon A?
e) Mengapa Balon B dan C Balon bergerak lebih cepat daripada Balloon A?
f) hukum ketiga Newton Negara dan menjelaskan bagaimana kegiatan ini menggambarkan hal
itu