Answer: a) electromagnetic waves
Explanation:
An electromagnetic wave begins when an electrically charged particle vibrates. This causes a vibrating electric field, which in turn creates a vibrating magnetic field. The two vibrating fields together form an electromagnetic wave.
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r = radius of the circle traveled by the particle = 76 cm = 0.76 m
T = time period of revolution for the particle = 4.5 s
w = angular velocity of the particle
angular velocity of the particle is given as
w = 2π/T
inserting the values
w = 2 (3.14)/4.5
w = 1.4 rad/s
a = centripetal acceleration of the particle in the circle
centripetal acceleration is given as
a = r w²
inserting the values
a = (0.76) (1.4)²
a = 1.5 m/s²
Having different densities being swirled rapidly will cause sedimentation. Sedimentation is the segmentation of the mixture creating layers of particles of these different densities. The process of rapid swirling is called differential centrifugation. An example use of this method is separation human blood into, red, platelet and white blood cells.
Answer;
Amount of time the two substances are in contact
Area in contact between the two substances
Specific heat of the material that makes up the substances
Explanation;
The change in temperature of a substance is caused by heat energy. The change in temperature will depend on factors such as mass of the substance, the type of material it is made from, the time taken , specific heat of the material that makes the substance, and also the area of contact.
The amount of time the two substances are in contact affect the change in temperature such that if the two bodies are in contact for a longer time then a bigger change in temperature will be observed.
Specific heat capacity also determines the change in temperature that will be observed, such that a substance with a bigger specific heat capacity will record a small change in temperature.
