Answer:
Angular momentum of the system is 4.8 kg m^2/s
Explanation:
As we know that the angular momentum of the system of masses is given as
here we have
now we also know that
now we have
Answer:
C. 0 J
Explanation:
When an object moves in a circle, friction provides the centripetal force. Hence, it is acting towards the centre of the circle. The displacement of the object is tangential to the circle at the point of interest. Hence, the angle between the frictional force and the displacement is 90°.
Work done is given by
<em>W</em> = <em>Fd</em> cos <em>θ</em>
where <em>F</em> is the force, <em>d</em> is the displacement and <em>θ</em> is the angle between them.
<em>W</em> = <em>Fd</em> cos 90° = 0 J
Hence, the work done by friction is 0 J.
Answer: The correct answer is (a).
Explanation:
The potential energy is due to the position of the object.
The kinetic energy is due to the motion of the object.
In the case of a basketball sitting on a shelf, the basketball posses the potential energy due to some height.
In the case of a dog running across a field, a dog has kinetic energy due to its motion.
In a case of a bowling ball rolling down a lane, there is kinetic energy due to the motion of the bowling ball.
In the case of a teenager riding their bike, there is kinetic energy due to the motion of the bike.
Therefore, the correct answer is (a).
and closing
.
The heart has 4 valves. They are what makes the lub-dub lub-dub sounds that can be heard from the chest.
The mitral valve is located between the left atrium and the left ventricle. It closes the left atrium to collect oxygenated blood from the lungs and opens to pass it on to the left ventricle.
The tricuspid valve is located between the right atrium and the right ventricle. It closes the right atrium to hold unoxygenated blood and opens to pass it on to the right ventricle ensuring a one way flow.
The aortic valve is located between the aorta and the left ventricle. It closes the left ventricle and opens to the aorta to pass on the oxygen-rich blood to the body.
The pulmonary valve is located between the pulmonary artery and the right ventricle. It closes off the right ventricle and opens to pass on unoxygenated blood to the lungs.
To solve this exercise it is necessary to take into account the concepts related to Tensile Strength and Shear Strenght.
In Materials Mechanics, generally the bodies under certain loads are subject to both Tensile and shear strenghts.
By definition we know that the tensile strength is defined as
Where,
Tensile strength
F = Tensile Force
A = Cross-sectional Area
In the other hand we have that the shear strength is defined as
where,
Shear strength
Shear Force
Parallel Area
PART A) Replacing with our values in the equation of tensile strenght, then
Resolving for F,
PART B) We need here to apply the shear strength equation, then
In such a way that the material is more resistant to tensile strength than shear force.
