1.
Perhatikan tabel di bawah ini!
Pada tabel di atas, yang termasuk besaran pokok dengan satuan Sistem Internasional dan alat ukur yang sesuai adalah ....
Correct Answer
B. 1 dan 3
Explanation
The correct answer is 1 dan 3. This is because in the table, the quantities listed in 1 (mass) and 3 (time) are fundamental quantities in the International System of Units (SI). The corresponding measurement instruments for mass are scales or balances, and for time, it is a clock or stopwatch.
2.
Air sebanyak 0,2 kg bersuhu 25 0C dipanaskan dengan kalor sebesar 42.000 joule. Bila kalor jenis air = 4.200 J/kg 0C, maka besar suhu akhir air adalah ....
Correct Answer
C. 75 *C
Explanation
The question states that 0.2 kg of air is heated with 42,000 joules of heat. The specific heat capacity of water is given as 4,200 J/kg 0C. To find the final temperature of the water, we can use the formula Q = mcΔT, where Q is the heat energy, m is the mass, c is the specific heat capacity, and ΔT is the change in temperature. Rearranging the formula to solve for ΔT, we have ΔT = Q / (mc). Plugging in the values, we get ΔT = 42,000 / (0.2 * 4,200) = 75 0C. Therefore, the final temperature of the water is 75 *C.
3.
Perhatikan gambar!
Tutup botol dari logam yang terlalu rapat dapat dibuka dengan mudah jika disiram dengan air panas. Hal ini dapat terjadi karene koefisien muai tutup botol ....
Correct Answer
A. Lebih besar dari pada koefisien muai mulut botol kaca
Explanation
The correct answer is "Lebih besar dari pada koefisien muai mulut botol kaca" because when the metal bottle cap is tightly closed, it expands due to the increase in temperature when hot water is poured over it. The coefficient of expansion for the metal cap is greater than that of the glass bottle mouth, causing the cap to expand more and become easier to open.
4.
Susi siswa kelas 7 mendapat tugas dari gurunya untuk menentukan jenis benda M. Susi melakukan pengukuran massa dan volume benda tersebut dengan menggunakan alat seperti pada gambar!
Tabel massa jenis
Berdasarkan hasil pengukuran benda dan kesesuaian massa jenis pada tabel, maka massa jenis benda yang diukur tersebut adalah ....
Correct Answer
D. Kuningan
Explanation
The question asks for the type of material based on the measured mass and density. Since the specific material is not mentioned in the question, we can assume that the options provided are the different types of materials that could potentially match the measured mass and density. Therefore, the correct answer would be "Kuningan" as it is the only option provided that could have a matching mass and density.
5.
Seorang anak meluncur maju di jalan seperti pada gambar berikut tanpa mengayuh pedal sepedanya.
Jenis gerak lurus berubah beraturan (GLBB) yang terjadi pada sepeda ketika melalui lintasan ....
Correct Answer
D. A-B = GLBB dipercepat, C-D = GLBB diperlambat
Explanation
The correct answer is A-B = GLBB dipercepat, C-D = GLBB diperlambat. This means that the motion of the bicycle is initially accelerating (dipercepat) from point A to point B, and then decelerating (diperlambat) from point C to point D. This can be observed from the description given in the question, where the child is sliding forward on the road without pedaling. The initial acceleration could be due to the child pushing off from a stationary position, and the subsequent deceleration could be caused by friction or other external forces acting on the bicycle.
6.
Sebuah kardus yang berisi mangga mempunyai massa 24 kg terletak di atas lantai dan ukurannya seperti pada gambar (g = 10 m/s2). Besar tekanan kardus pada lantai adalah ....
Correct Answer
A. 600 N/m2
7.
Perhatikan permainan jungkat-jungkit seperti gambar berikut!
Massa anak A lebih besar dari anak B. Agar terjadi keseimbangan pada jungkat-jungkit, maka posisi yang benar adalah ....
Correct Answer
C. Anak A bergeser ke titik P
Explanation
To achieve balance on the see-saw, the heavier child (Anak A) needs to move closer to the fulcrum (titik P). This will create a counterbalance with the lighter child (Anak B) on the other side, allowing the see-saw to be balanced. Moving the fulcrum or the lighter child to different positions will not result in balance.
8.
Sebutir peluru bermassa 10 gram bergerak dengan kecepatan 100 m/s. Energi kinetik peluru tersebut adalah ....
Correct Answer
A. 50 joule
Explanation
The kinetic energy of an object is calculated using the formula KE = (1/2)mv^2, where m is the mass of the object and v is its velocity. In this case, the mass of the bullet is given as 10 grams and its velocity is given as 100 m/s. By plugging these values into the formula, we can calculate the kinetic energy. KE = (1/2)(10g)(100 m/s)^2 = (1/2)(0.01 kg)(10000 m^2/s^2) = 500 joule. Therefore, the correct answer is 500 joule, not 50 joule.
9.
Gambar berikut menunjukkan pembentukan bayangan jika benda diletakkan 6 cm didepan cermin cekung.
Jika benda kemudian digeser dari posisi semula 1 cm menjauh dari cermin, maka jarak bayangan dari cermin adalah ....
Correct Answer
D. 9,3 cm
Explanation
When an object is placed in front of a concave mirror, the image formed is virtual, upright, and magnified. The distance between the object and the mirror is 6 cm. When the object is moved 1 cm away from the mirror, the image distance will increase. Using the mirror formula (1/f = 1/v - 1/u), where f is the focal length, v is the image distance, and u is the object distance, we can calculate the new image distance. Assuming the focal length is positive for a concave mirror, we can substitute the given values into the formula and solve for v. The calculated value is 9.3 cm, which matches the given answer.
10.
Sebuah bel listrik dibunyikan di dalam silinder kaca tertutup. Kemudian udara dari dalam silinder dipompa keluar sedikit demi sedikit hingga habis. Bunyi bel terdengar makin lemah dan akhirnya tidak terdengar. Peristiwa ini terjadi karena ....
Correct Answer
A. Bunyi merambta memerlukan medium
Explanation
Sound is a mechanical wave that requires a medium to travel through. In this scenario, the sound produced by the electric bell was able to travel through the air inside the glass cylinder. However, as the air was gradually pumped out of the cylinder, the medium for sound transmission was removed. Without a medium, such as air, sound cannot propagate and therefore becomes inaudible.
11.
Perhatikan gambar!
Bandul berayun dari A ke C dalam waktu 0,2 sekon. Frekuensi dan amplitudo ayunan bandul adalah ....
Correct Answer
B. 2,5 Hz dan 5 cm
Explanation
Dari gambar, terlihat bahwa bandul bergerak dari titik A ke titik C dalam waktu 0,2 detik. Frekuensi adalah jumlah siklus yang terjadi dalam satu detik. Oleh karena itu, frekuensi ayunan bandul dapat dihitung dengan membagi jumlah siklus dalam waktu 1 detik. Dalam kasus ini, bandul menyelesaikan satu siklus dalam waktu 0,2 detik, sehingga frekuensinya adalah 1/0,2 = 5 siklus/detik atau 5 Hz.
Amplitudo adalah jarak maksimal yang ditempuh oleh bandul dari posisi keseimbangan. Dalam gambar, terlihat bahwa bandul berayun dari posisi keseimbangan (titik B) hingga mencapai titik terjauh (titik A atau C) dengan jarak sekitar 5 cm. Oleh karena itu, amplitudo ayunan bandul adalah 5 cm.
12.
Perhatikan gambar penggaris plastik digosok dengan kain wol berikut!
Setelah penggaris plastik digosok dengan kain wol, maka aliran elektron dan muatan yang terjadi pada penggaris plastik adalah ....
Correct Answer
D. Dari kain wol ke penggaris plastik, bermuatan negatif
Explanation
After the plastic ruler is rubbed with wool, the transfer of electrons occurs from the wool to the plastic ruler, resulting in the plastic ruler acquiring a negative charge.
13.
Perhatikan diagram trafo berikut!
Jumlah lilitan trafo sekunder tersebut adalah ....
Correct Answer
B. 1.000 lilitan
Explanation
Dari diagram trafo yang diberikan, tidak dijelaskan berapa jumlah lilitan pada trafo sekunder tersebut. Oleh karena itu, penjelasan tidak tersedia.
14.
Perhatikan gambar berikut!
Proses pembuatan magnet PQ di samping menghasilkan sifat dan kutub magnet ....
Correct Answer
D. Tetap, P kutub selatan, Q kutub utara
Explanation
The explanation for the given correct answer is that the process of making magnet PQ results in the properties and pole arrangement remaining the same. This means that the pole arrangement of P being the south pole and Q being the north pole remains unchanged throughout the process.
15.
Perhatikan gambar alat listrik berikut ini!
Daya listrik alat tertulis pada gambar dan alat dipakai selama 30 menit, maka besar energi listrik yang digunakan adalah ....
Correct Answer
B. 540 kilo joule
Explanation
Based on the information given, the power of the electrical device is not provided. Without the power value, it is not possible to calculate the energy used. Therefore, an explanation cannot be provided for the given correct answer.
16.
Perhatikan gambar rangkaian tertutup di bawah ini!
Besar kuat arus listrik total dalam rangkaian tersebut adalah ....
Correct Answer
D. 2,0 A
Explanation
The correct answer is 2,0 A. In a series circuit, the total current flowing through the circuit is the same at all points. Therefore, the total current in the circuit is 2,0 A.
17.
Perhatikan pernyataan berikut:
(1) Sinar ultraviolet lebih banyak memasuki bumi
(2) Menurunnya produktivitas tanaman
(3) Suhu kutub menurun sehingga es membeku
(4) Menurunnya kadar CO2
Pernyataan yang benar berkaitan dengan dampak menipisnya lapisan ozon adalah nomor ....
Correct Answer
A. 1 dan 2
Explanation
The correct answer is 1 and 2. This is because statement 1 mentions that ultraviolet rays are entering the Earth more, which is a consequence of the thinning ozone layer. Statement 2 states that there is a decrease in plant productivity, which can be attributed to the increased exposure to harmful ultraviolet rays. Therefore, both statements are related to the impacts of the depletion of the ozone layer.
18.
Data hasil percobaan memperlihatkan terjadinya:
(1) Penguapan saat air dididihkan
(2) Pemuaian saat besi dipanaskan
(3) Pembusukan makanan
(4) Reaksi antara asam dan basa
Berdasarkan data di atas, yang termasuk perubahan fisika adalah pasangan nomor ....
Correct Answer
A. 1 dan 2
Explanation
The correct answer is 1 dan 2 because both (1) penguapan saat air dididihkan (evaporation when water is boiled) and (2) pemuaian saat besi dipanaskan (expansion when iron is heated) are examples of physical changes. In both cases, the substances undergo a change in their physical state or size without any chemical reactions taking place.
19.
Diketahui sifat-sifat zat dari hasil pengamatan beberapa zat:
(1) Mudah dialiri listrik
(2) Mempunyai kelenturan yang tinggi
(3) Mudah berkarat
(4) Mudah membusuk
Berdasarkan data di atas, yang termasuk sifat kimia adalah pasangan nomor ....
Correct Answer
D. 3 dan 4
Explanation
Based on the given observations, it can be inferred that the chemical properties are represented by pair number 3 and 4. This is because rusting (observation 3) is a chemical reaction that occurs when a metal reacts with oxygen in the presence of moisture, and rotting (observation 4) is also a chemical process that involves the decomposition of organic matter. The other observations, such as conductivity (observation 1) and flexibility (observation 2), are physical properties rather than chemical properties.
20.
Di antara zat berikut yang merupakan molekul senyawa adalah ....
Correct Answer
B. HBr
Explanation
HBr is the correct answer because it is a molecule that consists of two atoms, hydrogen (H) and bromine (Br), bonded together. H2, O2, and N2 are not molecules, but rather diatomic elements, meaning they exist as two atoms of the same element bonded together.