Answer:
Option B
Explanation:
Option A is the wrong answer because the horizontal vector is in the opposite direction.
Option C is the wrong answer as the horizontal vector is in the opposite direction and all the vectors are connected head to tail [of the arrows] [Triangle law of vector addition]
Option D is the wrong answer as the horizontal vector is in the opposite direction.
The answer will be 50N.
This is because the spring reads weight and weight is mass times acceleration due to gravity.5kg*10m/s2=50N
The kinetic energy of the ejected electrons will be 2782.5 ×10⁻²² eV.
<h3>What is threshold frequency?</h3>
The threshold frequency of incoming radiation is the lowest frequency at which photoelectric emission or electron emission is impossible.
The threshold frequency is the light frequency that causes an electron to dislodge and emit from the metal's surface.
From the photoelectric effect, the equation obtained as;
Hence,the kinetic energy of the ejected electrons will be 2782.5 ×10⁻²² eV.
To learn more about the threshold frequency, refer to the link;
brainly.com/question/2499414
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2.3 seconds
Ignoring air resistance, the flight time is merely a function of gravity and vertical velocity. The vertical velocity will be the initial velocity multiplied by the sine of the angle above the horizon. So:
V = sin(72)*12 m/s
V = 0.951056516 * 12 m/s
V = 11.4126782 m/s
Gravitational acceleration is 9.8 m/s, so divide the vertical velocity by gravitational acceleration to get how long it takes for the ball to reach its apex.
11.4126782 m/s / 9.8 m/s^2 = 1.164559 s
And the old saying "What goes up, must come down" really applies here. And conveniently, it's also symmetric, in that the time it takes to fall will match the time it takes to reach its apex. So multiply the time by 2.
1.164559 s * 2 = 2.329117999 s
Rounding the result to 2 significant figures gives 2.3 seconds.
