The ball can't reach the speed of 20 m/s in two seconds, unless you THROW it down from the window with a little bit of initial speed. If you just drop it, then the highest speed it can have after two seconds is 19.6 m/s .
If an object starts from rest and its speed after 2 seconds is 20 m/s, then its acceleration is 20/2 = 10 m/s^2 .
(Gravity on Earth is only 9.8 m/s^2.)
Reading a book in your warm, comfy seat ... in Row-27 of a
passenger airliner cruising at 450 miles per hour.
The work done on the box by the applied force is zero.
The work done by the force of gravity is 75.95 J
The work done on the box by the normal force is 75.95 J.
<h3>The given parameters:</h3>
- Mass of the box, m = 3.1 kg
- Distance moved by the box, d = 2.5 m
- Coefficient of friction, = 0.35
- Inclination of the force, θ = 30⁰
<h3>What is work - done?</h3>
- Work is said to be done when the applied force moves an object to a certain distance
The work done on the box by the applied force is calculated as;

where;
a is the acceleration of the box
The acceleration of the box is zero since the box moved at a constant speed.

The work done by the force of gravity is calculated as follows;

The work done on the box by the normal force is calculated as follows;

Learn more about work done here: brainly.com/question/8119756
Answer:
Acceleration, 
Explanation:
It is given that,
Separation between the protons, 
Charge on protons, 
Mass of protons, 
We need to find the acceleration of two isolated protons. It can be calculated by equating electric force between protons and force due to motion as :


So, the acceleration of two isolated protons is
. Hence, this is the required solution.