Please help with this question !!!!!

Answer:

30m/s

Explanation:

Given parameters:

Distance  = 12m

Time taken  = 0.4s

Unknown:

Velocity of the tennis ball = ?

Solution:

Velocity of a body is the displacement per unit of time.

  Velocity  = [tex]\frac{displacement}{time}[/tex]  

So;

      Velocity  = [tex]\frac{12}{0.4}[/tex]   = 30m/s

Answer:

2 atoms

Explanation:

Answer:

vasporisation

Explanation:

process used to change liquid to gass

Answer:

I believe it's Evaportation or another word would be Vaporisation.

Explanation:

hope this helps! ^^

Answer:

12 joules

Explanation:

I'm assuming you're looking for kinetic energy?? Kinetic energy is 1/2 mv^2. 4 squared is 16, 16 times 1.5 = 24. 24/2 = 12.

Answer:

Kinetic energy, form of energy that an object or a particle has by reason of its motion. ... Kinetic energy is a property of a moving object or particle and depends not only on its motion but also on its mass.

Credits to britannica.com

Explanation:

Hope this helps

Kinetic energy of an object is the energy that it possesses due to its motion.

Explanation:

Refractive Index is a value calculated from the ratio of the speed of light in a vacuum to that in a second medium of greater density. The refractive index variable is most commonly symbolized by the letter ‘n’ or n’ in a descriptive text and mathematical equations.

Answer:

Speed is constant but velocity is changing

Explanation:

Speed is a scalar quantity, meaning magnitude only. Velocity is a vector quantity, meaning magnitude and direction. If you're moving in a circle at a constant speed, the speed is constant but the direction is constantly changing. Therefore, the speed is constant but velocity changes.

Answer:

I'm fairly certain it's 1,800

Explanation:

The efficiency of the wedge with force F=900 N displaces the wedge 0.10 m is 55.55%  or 56%.

The efficiency of the machine equals the ratio of output energy and input energy. It is also defined as the ratio of work done on a load by the machine to the work done on the effort by the machine.

A load is defined as the weight lifted by the machine. The effort is defined as the force applied to bring the desired change in the load. Work done is defined as the product of force and displacement.

The efficiency, η = Output power / Input power, and the highest efficiency of the machine is equal to one. The efficiency of the machine has no unit. The efficiency η = (Actual work done / Ideal work done) × 100.

From the given,

Force = 900 N

Displacement = 0.1 m

Work done = F × s = 900×0.1 = 90 J

Actual work done = 50 J

Efficiency,η = (50/90) × 100

           η  = 55.55 %

Thus, the efficiency of the wedge is 55.56%.

To learn more about the Efficiency of a machine:

https://brainly.com/question/11752408

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