We are given with the expression d = ut + 0.5 at^2 and is asked to express the equation in terms of a. First, we transpose ut to the left side, then we multiply to the equation and divide lastly the resulting equation by t^2. The final expression becomes a = 2(d-ut)/t^2.
To solve this problem we will apply the principles of energy conservation. On the one hand we have that the work done by the non-conservative force is equivalent to -30J while the work done by the conservative force is 50J.
This leads to the direct conclusion that the resulting energy is 20J.
The conservative force is linked to the movement caused by the sum of the two energies, therefore there is an increase in kinetic energy. The decrease in the mechanical energy of the system is directly due to the loss given by the non-conservative force, therefore there is a decrease in mechanical energy.
Therefore the correct answer is A. Kintetic energy increases and mechanical energy decreases.
The force tending to lift the load (vertical force) is equal to <u>22.5N.</u>
Why?
Since the boy is pulling a load (150N) with a string inclined at an angle of 30° to the horizontal, the total force will have two components (horizontal and vertical component), but we need to consider the given information about the tension of the string which is equal to 105N.
We can calculate the vertical force using the following formula:

Hence, we can see that <u>the force tending to lift the load</u> off the ground (vertical force) is equal to <u>22.5N.</u>
Have a nice day!
Answer:
Buoyancy force and surface tension are the reactions that take places between soap and pepper experiment.
Explanation:
Surface tension:
The surface tension of a liquid is the tendency of liquid surfaces to resist an external force due to the cohesive nature of its molecules.
The pepper and soap experiment helps you to understand buoyancy force and surface tension.
Reaction between the pepper and soap is as following.
- The pepper flakes float because of buoyancy force. It makes the pepper flakes to move away to the edge of the plate.
- This happens because the liquid dish soap changes the surface tension of water.
- And The pepper flakes are so light, it floats on the water surface due to surface tension.
- when we add soap, it breaks the surface tension of water, but the water resists it. So they pull away from the soap along with the pepper flakes.
- This pushes the pepper away from your soap covered finger.
This is the reaction that take places between soap and pepper experiment.
Learn more about Pepper and soap experiment here:
<u>brainly.com/question/9614070</u>
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Answer:
It is the ratio of the density of a substance to the density of a given reference material.
Explanation:
<em>Specific gravity is also known as relative density.</em>
<u>To find the relative density of substance, you:</u>
- Divide the density of substance measured
- And divide that by the density of the reference