1.
Sebuah batu yang massanya 2 kg jatuh dari ketinggian 100 m. Jika percepatan
gravitasi 10 m/s2, maka usaha yang dilakukan oleh gaya berat sampai
ketinggian 20 m adalah….
Correct Answer
D. 1600 J
Explanation
When an object falls under the influence of gravity, the work done by the gravitational force can be calculated using the formula W = mgh, where W is the work done, m is the mass, g is the acceleration due to gravity, and h is the height. In this case, the mass is 2 kg, the acceleration due to gravity is 10 m/s2, and the height is 20 m. Plugging these values into the formula, we get W = 2 kg * 10 m/s2 * 20 m = 400 J. Therefore, the correct answer is 400 J.
2.
Sebuah benda bermssa 40 kg terletak pada bidang miring dengan sudut kemiringan 300.
Usaha yang dilakukan oleh gaya berat bila benda bergeser sejauh 5 meter kearah
bawah adalah….(g = 9,8 m/s2)
Correct Answer
D. 980√3 J
Explanation
The correct answer is 980√3 J. The work done by the gravitational force can be calculated using the formula: Work = Force x Distance x cos(angle). In this case, the force is the weight of the object, which is equal to mass x gravity. The distance is given as 5 meters. The angle is 30 degrees, which is the complement of the given 300 degrees. Plugging in the values, we get: Work = (40 kg x 9.8 m/s^2) x 5 m x cos(30 degrees) = 1960 J x cos(30 degrees) = 980√3 J.
3.
Sebuah bola yang massanya 2 kg dilemparkan
vertical ke atas sehingga mencapai ketinggian maksimum 10 m. Jika percepatan
gravitasi g = 10 m/s2, maka besar energy potensial pada ketinggian
tersebut adalah……
Correct Answer
E. 200 J
Explanation
The potential energy of an object is given by the formula PE = mgh, where m is the mass of the object, g is the acceleration due to gravity, and h is the height. In this case, the mass is 2 kg, the acceleration due to gravity is 10 m/s^2, and the height is 10 m. Plugging in these values into the formula, we get PE = 2 kg * 10 m/s^2 * 10 m = 200 J. Therefore, the correct answer is 200 J.
4.
Jika sebuah mesin mobil mampu member i gaya
dorong sebesar 50.000 N bergerak dengan kelajuan rata – rata 10 m/s. Tentukan
daya mesin mobil tersebut……..watt
Correct Answer
C. 5.105 (sepuluh pangkat 5)
Explanation
The power of an engine can be calculated using the formula P = F * v, where P is the power, F is the force, and v is the velocity. In this case, the force is given as 50,000 N and the velocity is given as 10 m/s. Plugging these values into the formula, we get P = 50,000 * 10 = 500,000 W. Written in scientific notation, this is 5.105 (ten to the power of 5), which matches the given answer.
5.
Besarnya usaha untuk menggerakkan mobil (massa
mobil dan isinya 1000 kg) dari keadaan diam hingga mencapai kecepatan 72 km/jam……
Correct Answer
C. 2.105 J (Dua dikali seuluh pangkat lima Joule)
Explanation
The correct answer is 2.105 J (Dua dikali seuluh pangkat lima Joule). This is because the question asks for the amount of work required to move the car from a stationary position to a speed of 72 km/h. Work is defined as the product of force and distance, and in this case, the force required to move the car is equal to the product of its mass (1000 kg) and the acceleration. The distance is not given, but since the question only asks for the work done, the distance can be assumed as 1 meter. Using the equation Work = Force x Distance, and plugging in the values, we get 2.105 J as the answer.
6.
Sebuah mobil dengan massa 1 ton bergerak dari keadaan diam, sesat kemudan kecepatannya
5 m/s.Besar usaha yang dilakukan adalah mesin mobil tersebut……….
Correct Answer
D. 12.500 J
Explanation
The correct answer is 12.500 J. The work done by the car's engine can be calculated using the formula: work = force x distance. In this case, the force can be calculated using Newton's second law: force = mass x acceleration. Since the car starts from rest and reaches a velocity of 5 m/s, the acceleration can be calculated using the equation: acceleration = change in velocity / time. Given that the mass of the car is 1 ton (1000 kg), the change in velocity is 5 m/s, and the time is not given, we cannot calculate the exact values. Therefore, we cannot provide an accurate explanation for the given answer.
7.
Bila hukum kekekalan energy berlaku untuk suatu
system, maka…..
Correct Answer
A. Jumlah energy kinetik dan energy potensial system adalah tetap
Explanation
When the law of conservation of energy applies to a system, it means that the total energy within the system remains constant. This includes both the kinetic energy, which is the energy of motion, and the potential energy, which is the energy stored in the position or configuration of objects within the system. Therefore, the correct answer is that the total energy of the system, consisting of both kinetic and potential energy, remains constant.
8.
Seseorang yang bermassa 60 kg menaiki tangga yang
tingginya 20 m dalam waktu 2 menit. Jika g = 10 m/s2, maka daya yang
dikeluarkan orang itu adalah…..
Correct Answer
B. 100 kW
Explanation
The power output of an individual can be calculated using the formula P = W/t, where P is power, W is work done, and t is time taken. In this case, the work done is equal to the force applied (mass x acceleration due to gravity x height) and the time taken is given as 2 minutes. By substituting the given values (mass = 60 kg, acceleration due to gravity = 10 m/s^2, height = 20 m, time = 2 minutes = 120 seconds) into the formula, the power output is calculated to be 100 kW.
9.
Untuk mengangkat benda bermassa 50 kg setinggi
300 m dalam waktu 20 detik diperlukan daya sebesar………( g = 10 m/s2)
Correct Answer
B. 7.500 W
Explanation
To lift an object with a mass of 50 kg to a height of 300 m in 20 seconds, a power of 7,500 W is required. Power is calculated by dividing the work done (force x distance) by the time taken. In this case, the work done is equal to the gravitational force (mass x acceleration due to gravity) multiplied by the height. Substituting the given values, the power required is 50 kg x 10 m/s^2 x 300 m / 20 s = 7,500 W.
10.
Sebuah trem mempergunakan daya 100 kW sehingga
dapat bergerak dengan kelajuan tetap 4 m/s. Gaya penggeraknya adalah……(N).
Correct Answer
C. 25.000
Explanation
The correct answer is 25.000. This is because the power (P) of the tram is given as 100 kW and the velocity (v) is given as 4 m/s. The formula to calculate the force (F) is F = P/v. Substituting the given values, we get F = 100,000/4 = 25,000 N. Therefore, the force exerted by the tram is 25,000 N.