Answer:
A. 20 N down
Explanation:
It's asking how much force of gravity is acting on it. The book weighs 20 Newtons so that's how much gravity is being applied. Hope this helps
The power dissipated by the LED is 20 Watts and the work done for 1 hour 15 minutes is 56.25 kJ.
<h3>What is electrical power?</h3>
Electrical power is the rate at which electrical work is done.
- Electrical power = voltage × current
The LED is 75% efficient means that 75% of power dissipated by the LED is converted to light.
Total power dissipated = 5 × 2.5 = 12.5 Watts
- Work done = power × time (in seconds)
Work done = 12.5 × (1 × 3600 + 15 × 60)
Work done = 56250 J = 56.25 kJ
Therefore, the power dissipated by the LED is 20 Watts and the work done for 1 hour 15 minutes is 56.25 kJ.
Learn more about electrical power and work done at: brainly.com/question/23901751
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Answer: 26.67 m/s
Explanation:
Given
Length traveled by the ball 
Time taken to reach the goal post is 
Initial velocity 
Using the second equation of motion

Now using

The velocity of ball will be 26.67 m/s
Answer:
(A) Equation will be 
(B) RMS value of voltage will be 0.530 volt
Explanation:
We have given peak to peak voltage of ac wave = 1.5 volt
Peak to peak voltage of ac wave is equal to 2 times of peak voltage
So 

Frequency of ac wave is given f = 3 kHz
So angular frequency
= 2×3.14×3000 = 18840 rad/sec
So expression of equation will be
( As phase difference is 0 )
Now we have to find the rms value of voltage
So rms voltage will be equal to 