Correct Answers is A.
The machines gives us some mechanical advantage. This means the mechanical average makes the work output greater than the work input
Simple most example is a lever. The force applied is smaller and the output work is larger as compared to input.
Option B cannot be true, as there must be a force to get some work done.
Option C and D are inverse of what a machine is designed for. A small force can be exerted through a large distance to have a large force exerted through a small distance. Common Example of this principle is a screw opener.
Hydroelectric power. That's just the term for electricity gained by using water, think of a water mill.
Answer:
90 ohms
Explanation:
1/r = 1/180 + 1/180
1/r= 2/180
take the reciprocal of 2/180 which is 180/2 and its 90 ohms
Answer:
A vacuum
Explanation:
Sound waves are examples of mechanical waves. Mechanical waves are waves which are transmitted through the vibrations of the particles in a medium.
For example, sound waves in air consist of oscillations of the air particles, which vibrate back and forth (longitudinal wave) along the direction of propagation of the wave itself.
Given this definition of mechanical wave, we see that such a wave cannot propagate if there is no medium, because there are no particles that would oscillate. Therefore, among the choices given, the following one:
a vacuum
represent the only situation in which a sound wave cannot propagate through: in fact, there are no particles in a vacuum, so the oscillations cannot occur. In all other cases, instead, sound waves can propagate.
The Mercury's mass for the given acceleration due to gravity is 0.3152 x 10²⁴ kg.
The ratio of the calculated and accepted value of the Mercury's mass is 0.95.
<h3>What is mass?</h3>
Mass is the amount of matter present in the object.
The mass of the object is always constant, anywhere it is on the Earth or Moon or any other planet.
Given is the acceleration due to gravity of Mercury planet at North pole is g = 3.698 m/s² and the radius of Mercury planet is 2440 km.
The acceleration due to gravity is related with mass as
g = GM/R²
Substitute the values, we have
3.698 = 6.67 x 10⁻¹¹ x M/(2440 x1000)³
M = 2.2016 x 10¹³ / 6.67 x 10⁻¹¹
M = 0.3152 x 10²⁴ kg
Thus, the mercury's mass is 0.3152 x 10²⁴ kg.
(b) Accepted value of Mercury's mass is 3.301 x 10²³ kg
Ratio of the value of mass calculated and accepted is
Mcalc/M accep = 0.3152 x 10²⁴ kg / 3.301 x 10²³ kg
= 0.95
Thus, the ratio is 0.95
Learn more about mass.
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