Answer: Light of frequency 5 x 1014 HZ liberates electrons with energy 2.3 x 10-19from a certain metallic surface.
Explanation:
Experimental Evidence.
Scientists conduct experiments or observations to gather evidence that either support or disprove a given hypothesis. Hence, all the scientific explanations are based on this body of observations.
Answer:
Given:
Radius of curvature (R) of a spherical mirror = 20
To Find:
Focal length (f)
Explanation:
Formula:
Substituting value of R in the equation:
Answer:
A) the current in AC electricity varies in magnitude and direction.
C) the voltage in AC electricity varies in magnitude and direction.
Explanation:
In DC current and voltage the direction of current will not change with time and it always remains the same.
So here in DC voltage and DC current the magnitude may change with time but the direction will always remain same
While in AC voltage and AC current the direction of AC will change with time
periodically.
So here magnitude and direction both will change in AC current and AC voltage.
so the correct answer is
A) the current in AC electricity varies in magnitude and direction.
C) the voltage in AC electricity varies in magnitude and direction.
So the acceleration of gravity is 9.8 m/s so that’s how quickly it will accelerate downwards. You can use a kinematic equation to determine your answer. We know that initial velocity was 19 m/s, final velocity must be 0 m/s because it’s at the very top, and the acceleration is -9.8 m/s. You can then use this equation:
Vf^2=Vo^2+2ax
Plugging in values:
361=19.6x
X=18 m
