1.
Penyebab langsung gerak rotasi adalah ..............
Correct Answer
C. Momen gaya
Explanation
The direct cause of rotational motion is the moment of force, also known as torque or moment of force. This is because torque is the product of force and the perpendicular distance from the axis of rotation. When a force is applied at a distance from the axis of rotation, it creates a torque that causes the object to rotate. Therefore, the correct answer is "Momen gaya", which translates to "moment of force" in English.
2.
Sebuah batang besi homogen bermassa 4 kg dan panjang 0,25 m. jika sumbu pusatnya terletak pada titik tengah dan tegak lurus batang, berapakah momen inersia batang besi (I=1/12 Ml2) tersebut.....
Correct Answer
E. 0,020 kg.m2
Explanation
The moment of inertia of a homogeneous rod with mass M and length L, with its center of mass located at the midpoint and perpendicular to the rod, is given by the formula I = (1/12)ML^2. In this case, the mass of the rod is 4 kg and the length is 0.25 m. Plugging these values into the formula, we get I = (1/12)(4 kg)(0.25 m)^2 = 0.020 kg.m^2. Therefore, the correct answer is 0.020 kg.m^2.
3.
Berikut ini hal-hal yang berhubungan dengan gerak rotasi :1. kecepatan sudut2. letak sumbu rotasi3. bentuk benda4. massa bendafaktor-faktor yang mempengaruhi besarnya momen inersia adalah ....
Correct Answer
D. 1,2,3,4
Explanation
The correct answer is 1,2,3,4. This is because all of the factors listed (kecepatan sudut, letak sumbu rotasi, bentuk benda, massa benda) can affect the magnitude of moment of inertia. Moment of inertia is a measure of an object's resistance to changes in its rotational motion, and it depends on factors such as the distribution of mass and the shape of the object. Therefore, all of the factors listed can contribute to the moment of inertia of an object undergoing rotational motion.
4.
Momen inersia suatu benda yang berotasi dengan kecepatan sudut 10 rad/s dan memiliki energi kinetik 5 joule adalah .......
Correct Answer
A. 0,1 kg.m2
Explanation
The moment of inertia of a rotating object is a measure of its resistance to changes in its rotational motion. It depends on the mass distribution of the object and the axis of rotation. The formula for moment of inertia is I = 0.5 * m * r^2, where m is the mass of the object and r is the distance from the axis of rotation. In this question, the moment of inertia is not directly given, but the kinetic energy and angular velocity are given. The formula for kinetic energy in rotational motion is KE = 0.5 * I * ω^2, where ω is the angular velocity. By rearranging the formula and substituting the given values, we can solve for I. In this case, I = KE / (0.5 * ω^2) = 5 / (0.5 * 10^2) = 0.1 kg.m^2. Therefore, the correct answer is 0.1 kg.m^2.
5.
Sebuah benda memiliki momen inersia 4 kg.m2, jika benda berputar dengan kecepatan sudut 3 rad/s2, maka besar momen gaya benda tersebut adalah .....
Correct Answer
C. 12 N.m
Explanation
The moment of inertia (I) of an object is a measure of its resistance to changes in rotational motion. The formula for calculating the moment of inertia is I = m*r^2, where m is the mass of the object and r is the distance from the axis of rotation. In this case, the moment of inertia is given as 4 kg.m^2. The formula for calculating the torque (moment of force) is torque = I * α, where α is the angular acceleration. The angular acceleration is given as 3 rad/s^2. By substituting the given values into the formula, we get torque = 4 kg.m^2 * 3 rad/s^2 = 12 N.m. Therefore, the correct answer is 12 N.m.
6.
Di bawah ini adalah faktor-faktor yang mempengaruhi momen inersia, kecuali ....
Correct Answer
C. Struktur bentuk benda
Explanation
The factors that affect moment of inertia are mass of the object, center of mass of the object, position of the axis of rotation, and angular velocity of the object. The structure or shape of the object does not directly affect the moment of inertia.