Gravity slows the upward speed of any rising object by 9.8 m/s every second.
If the ball is tossed upward at 20 m/s, then it's at the top of its arc and its speed has dwindled to zero in (20/9.8) = 2.04 seconds.
During that time, its starting speed is 20 m/s and its ending speed is zero, so its AVERAGE speed all the way up is (1/2) (20 + 0) = 10 m/s .
Sailing upward for 2.04 seconds at an average speed of 10 m/s, the ball rises to (2.04 x 10) = <em>20.4 meters.</em>
The gravitational attraction between two planets is 4905.95 N
<h3>What is gravitational attraction?</h3>
When two objects with masses are placed at a distance, there will an attractive force acting between them.
According to the Newton's law of gravitation, gravitational force is
F = Gm₁m₂ /r²
where r is the distance between the masses m₁ and m₂ and G is the gravitational constant G = 6.67 x 10⁻¹¹ N-m²/kg²
Substitute the values into the expression, we get
F = 6.67 x 10⁻¹¹ x 2.25 x 10²⁰ x 6.20 x 10¹⁸ / (435,500 x 1000)²
F= 4905.95 N
Thus, the gravitational attraction between two planets is 4905.95 N.
Learn more about gravitational attraction.
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Protons have a positive charge
Answer:
(D ) 
and 
Explanation:
Given that, the rms value of current is 10 ampere and its frequency is 50 Hz.
Now maximum value of current can be calculated as,
The time period is defined as,
Now the time taken by alternating current going from zero to maximum value is,
Therefore, the time taken by alternating current to reach maximum value is 
and the peak value of current is .
