2. A rubber ball is dropped onto the floor from a height of ℎ metres. The time taken for it to stop bouncing is t seconds. This is given by the formula, where is a number that measures the ‘bounciness’ of the rubber ball. When dropped from a height of 1.25 m, it bounces for 2.5 s. a. Find the value of e b. For how long would the rubber ball bounce if it was dropped from a height of 1.8 m? c. The same rubber ball is dropped again, and this time it bounces for 3.5 s. find the height that it was dropped from.
1. 2. A rubber ball is dropped onto the floor from a height of ℎ metres. The time taken for it to stop bouncing is t seconds. This is given by the formula, where is a number that measures the ‘bounciness’ of the rubber ball. When dropped from a height of 1.25 m, it bounces for 2.5 s. a. Find the value of e b. For how long would the rubber ball bounce if it was dropped from a height of 1.8 m? c. The same rubber ball is dropped again, and this time it bounces for 3.5 s. find the height that it was dropped from.
a. [tex]t=(\frac{1+e}{1-e})\sqrt{\frac{h}{5}}\\2,5=(\frac{1+e}{1-e})\sqrt{\frac{1,25}{5}}\\2,5=(\frac{1+e}{1-e})\cdot0,5\\\frac{2,5}{0,5}=\frac{1+e}{1-e}\\5-5e=1+e\\6e=4\\e=\frac{4}{6}\\[/tex]
b. & c. just substitution the variable
Good luck
2. A ball with a mass of 200g is placed on a compressed spring. The spring is then released and the ball bounces up. The compressed spring has 5 3 of elastic potential energy. : (a) Calculate the speed of the ball immediately when the ball bounces up. (b) What is the height that can be reached by the ball from the position it was released? [gravitational acceleration = 10ms ³]soal A nya saja please
Jawaban:
Gk tau
Penjelasan:
Gk bisa bahasa inggris :v
3. a 2 kg metal ball is suspended from a rope as a pendulum. If it is released from point A and swings down to point B calculate the velocity of the ball at point B!
m.g.hA = 1/2.m.vB²
vB² = 2.g.hA
vB² = 2. 10. 0,5 = 10
vB = √10 m/s
the velocity of the ball at point B is √10 m/s.
4. A ball is thrown vertically upwards and reaches its maximum height 2.0 s later a. What is the initial velocity of the ball? b. What is the maximum height that the ball reaches?
Jawaban:
a. 20m/s
b.20m
Penjelasan:
Given : Time taken to reach the maximum height t=2 s
a=−g=−10m/s ^2
The initial velocity of the ball can be calculated by,
Using v=u+at
∴ 0=u−10×2 ⟹u=20 m/s
Using S = ut + 1/2at^2
S = 20.2 + 1/2 (-10)(2)^2
S = 40 + (-20)
S = 20m (the maximum height)
5. Rubber (...) from vulcanized silicones with a high molecular weight isdifficolt to distinguish from natural rubber.(A) is produced(B) produced(C) that produces(D) producing
Rubber IS PRODUCED from vulcanized silicones with a high molecular weight is difficolt to distinguish from natural rubber.
6. Tolong dijawab kak A ball is kicked at an angle of 37° with the ground. Determine the initial velocity of the ball so that it hits a target that is 32 m away at a height of 4 m.
Jawaban:
20 m/s
Penjelasan:
Sx = V0x . t
32 = V0 . cos 37° . t
t = 32 / V0 . cos 37°
t = 32 / V0 . 4/5
t = 40 / V0
V0y = V0 . sin 37°
V0y = 3/5 V0
Sy = V0y . t + 1/2 g . t²
4 = (3/5 V0) . (40 / V0) + 1/2 . (-10) . (40 / V0)²
4 = 24 - 5 (40 / V0)²
- 20 = - 5 (40 / V0)²
(40 / V0)² = -20/-5
(40 / V0)² = 4
40 / V0 = 4
40 = 2 V0
V0 = 20 m/s
7. You drop a ball from a height of 2.0 m, and it bounces back to a height of 1.6 m. (a) What fraction of its initial energy is lost during the bounce? (b) What is the ball’s speed just before and just after the bounce? (c) Where did the energy go?
Jawaban sudah saya tulis di atas.
8. Physics IGCSE 0625/21/M/J/18 A ball of mass 1.2 kg is deopped from a height of 30 m. As it falls, 25% of its initial gravitational potential energy is transferred to thermal energy. What is the kinetic energy of the ball just before it hits the ground?
Jawaban:
Energi potensial (Ep)
Ep = mgh
= 1,2×10×30
= 12×30
= 360 J
Karena ada energi yang hilang (thermal energy), maka tidak ada konservasi energi
E thermal = 25% Ep
= 1/4 Ep
= 1/4×360
= 90 J
Ep = E thermal + Ek
360 = 90 + Ek
Ek = 270 J
Jawaban:
the kinetic energy of the ball just before it hits the ground is 270 Joule.
Penjelasan:
Conservation of mechanical energy states that the total energy of the system remains constant.
before the ball dropped, it has its potential energy defined by
Ep = m.g.h = (1.2)(10)(30) = 360 Joule
the kinetic energy is zero since the ball is at rest.
and when the ball hits the ground, the potential energy is zero while the kinetic energy becomes maximum.
since 25% of its initial potential energy is transferred to thermal energy, then the remaining potential energy is only 75%, it is 75% of 360 Joule = 270 Joule, and this is the only amount of energy that can be converted into kinetical energy then.
Therefore, the kinetic energy of the ball just before it hits the ground is 270 Joule.
Hopefully this is understandable and helpful.
Thank you
#TetapBelajar
#TetapSehat
#TetapJagaKesehatan
9. A table tennis ball is released from a height h above a table. 50% of kinetic energy is lost at each bounce and none is lost by friction with the air. The height reached after the second bounce is …………a. h√2 b. h/√2 c. h/2 d. h/4 e. h/8
Naskah soal :
A table tennis ball is released from a height h above a table. 50% of kinetic energy is lost at each bounce and none is lost by friction with the air. The height reached after the second bounce is …………
a. h√2 b. h/√2 c. h/2
d. h/4 e. h/8
Diketahui :
Ketinggian awal (h₁) = h
Energi kinetik yang hilang ( Ek₂) = 50 % Ek₁ = 0,5 Ek₁
Ditanya : Ketinggian ke 2 = ...........?
Jawab:
untuk menentukan ketinggian yang bkedua kita dapat menggunakan persamaan
EK₂ = 0,5 Ek₁
1/2 . m. v₂² = 0,5 . 1/2 . m. V₁²
V₂² = 0,5 V₁²
untuk kecepatan pada ketinggian pertama
V₁ = [tex] \sqrt{2.g.h} [/tex]
V₁² = 2. g .h₁
untuk kecepatan pada ketinggian kedua
V₂ = [tex] \sqrt{2.g (h_1 - h_2)} [/tex]
v₂² = 2.g (h₁ - h₂)
sehingga persamaanya menjadi
v₂² = 0,5 v₁²
2.g (h₁ - h₂) = 0,5 . g . h₁
h- h₂ = 0,5 h
h₂ = h – 0,5 h
h₂ = 0,5 h = 1/2 h = h/2 Jadi jawabannya adalah C.
PENJELASAN LEBIH LANJUT
Energi adalah kemampuan untuk melakukan usaha. Energi tidak dapat dimusnahkan. Energi hanya dapat berubah bentuk. Energi potensial adalah energi yang dimiliki benda karena kedudukannya (posisinya), yaitu
EP = m.g.h
Energi kinetik adalah energi yang dimiliki oleh benda yang bergerak, yaitu
EK =1/2 mv²
Energi mekanik adalah jumlah energi potensial dan energi kinetik yang terdapat pada benda, yaitu
EM = EP + EK
Hukum Kekekalan Energi Mekanik menyatakan bahwa energi mekanik benda tetap. Hukum iniberlaku apabila tidak terdapat gaya luar yang bekerja pada benda.
EM₁ = EM₂
EP₁ + EK₁ = EP₂ + EK₂
Pelajari soal-soal Usaha dan Energi lainnya melalui link berikut:
https://brainly.co.id/tugas/15636371
Selamat Belajar dan tetap Semangat!!!
-----------------------------------------------------------------------------------------------------------------
Kelas : XI
Mapel : FISIKA
BAB : USAHA dan ENERGI
Kata Kunci : Energi, Usaha, Kecepatan, Tinggi, Kinetik
Kode : 11.6.5.
-----------------------------------------------------------------------------------------------------------------
10. A ball A is thrown vertically upward from the top of a 30-m-high building with an initial velocity of 5 m/s. At the same instant another ball B is thrown upward from the ground with an initial velocity of 20 m/s. Determine the height from the ground and the time at which they pass.
Jawab:
Penjelasan dengan langkah-langkah:
11. A cone of base radius 5 cm and height 12 cm is placedover a solid rubber ball. The fit is 'perfect, so the conetouches the floor and the ball touches the cone.Find the radius of the ball.Hint:Show that triangles ABY and AXC are similar.
Arti:Sebuah kerucut dengan radius alas 5 cm dan tinggi 12 cm ditempatkan
di atas bola karet padat. Pasnya 'sempurna, jadi kerucutnya
menyentuh lantai dan bola menyentuh kerucut.
Temukan jari-jari bola.
Petunjuk:
Tunjukkan bahwa segitiga ABY dan AXC serupa.
follow akun saya nanti di folback
12. a ball with a mass of 2 kg is dropped from the top of a building and strikes the ground at a velocity of 10 m/s what is the heigt of the building from which the ball is dropped?
Materi : Kinematika Gerak Lurus
Sub materi : Gerak Jatuh Bebas
Mapel : Fisika
Kelas : X SMA (KTSP)
Keyword : GJB
ㅡㅡㅡㅡㅡㅡㅡㅡㅡㅡㅡㅡㅡㅡㅡㅡㅡㅡ
Diketahui :
m = 2 kg
v = 10 m/s
Ditanya :
h = ?
Penyelesaian :
Gerak jatuh bebas merupakan gerak benda dengan kecepatan awal benda Vo = 0 ,bisa dikatakan benda jatuh secara spontan.
Analisis soal :
A ball with a mass m kg dropped from the building which the height h meter. When the ball strikes, the velocity is 10m/s. The problem is what is the height of the building where the ball was dropped from?
Perhitungan :
v = √2gh
v² = 2gh
(10)² = 2(10)h
100 = 20h
h = 100/20
h = 5 m
So, the height of the building where the ball was dropped from is 5 m
-vin
13. The average average height of a good is 142 cm theheightis 138 cm. what is the height of the other girls?
Jawab:
Penjelasan dengan langkah-langkah:
Diketahui :
Rata-rata tinggi perempuan = 142 cm
x₁ = tinggi perempuan pertama = 138 cm
Ditanya : x₂
Jawab :
Rata-rata
=> (x₁ + x₂ ) / 2 = 142
=> (138 + x₂ ) = 2 * 142 = 284
=> x₂ = 284 - 138 = 146 cm
Tinggi perempuan kedua = 146 cm
14. a sepak takraw that is kicked from a height?
Jawaban:
A sepak takraw that is kicked from a height of two meters?
Penjelasan:
15. Rubber _____ from vulcanized silicones with a high molecular weight is difficult to distinguish from natural rubber.
Jawaban:
Rubber made from vulcanized silicones with a high molecular weight is difficult to distinguish from natural rubber
Penjelasan:
Untuk memahami kalimat di atas perhatikan bahwa bagian panjang:
Rubber made from vulcanized silicones with a high molecular weight adalah subjek kalimat, jadi harus dibaca secara satu kesatuan.
made di sana artinya bukan membuat tapi yang terbuat.
Semoga membantu
16. a warter reservoir at a height of 1.2 m is full of water. at the height of 90 cm from the water
90 cm = 0,09 m
12 m-0,09 m = 1,11 m
17. A ball is dropped from a height and hits the floor with a speed of 10 m/s. Then the ball bounces up with a speed of 4 m/s. Calculate: a. Impulse acting on the ball if the ball has a mass of 0.2 kg (20 poin)b. The force acting on the floor when the ball hits the floor for 0.01 second (20 poin)
Jawaban:
Penjelasan:
a. impulse acting to the ball is equal with the change of linear momentum
[tex]I=-\Delta P=-m(v_2-v_1)=-0.2kg(4m/s-10m/s)=7.2Ns[/tex]
b. the average force acting on the floor
[tex]I=F\Delta t=7.2 Ns=F(0.01s)\\F=720N[/tex]
18. a sepak takraw that is kicked from a height of two meters?
Jawaban:
sebuah sepak takraw yang ditendang dari ketinggian dua meter?
19. A ball is thrown vertically upwards and reaches its maximum height 2.0 s later a. What is the initial velocity of the ball? b. What is the maximum height that the ball reaches?
Given : Time taken to reach the maximum height t=2 s
a=−g=−10m/s ^2
The initial velocity of the ball can be calculated by,
Using v=u+at
∴ 0=u−10×2 ⟹u=20 m/s
Using S = ut + 1/2at^2
S = 20.2 + 1/2 (-10)(2)^2
S = 40 + (-20)
S = 20m (the maximum height)
20. a sepak takraw that is kicked from a height of two meters follows a path that is?
Jawaban:
sebuah sepak takraw yang ditendang dari ketinggian dua meter mengikuti jalan setapak itu?
0 Komentar