Speed, being a scalar quantity, is the rate at which an object covers distance. The average speed is the distance (a scalar quantity) per time ratio. ... Velocity is the rate at which the position changes. The average velocity is the displacement or position change (a vector quantity) per time ratio.
Cars are the mechanical device which convert chemical energy of fuel into mechanical energy, the engine used in the automobiles car are very inefficient, they can only convert 30-40% of chemical energy of fuel into mechanical energy, since thermodynamics is the branch of science that deals with the conversion of energy, thus due to poor conversion rate of chemical energy into mechanical energy, cars are known as inefficient machine.
Answer:
F = 47.6 N
Explanation:
- Newton's 2nd law can be expressed as the rate of change of the total momentum, respect of time, as follows:

- So, in order to find the average force exerted by the skater on the wall, we can find the change in momentum due to the force exerted by the wall (which is equal and opposite to the one exerted by the skater), and divide it by the time interval , as follows:

⇒ Fsk = 47.6 N (normal to the wall)
The ones with pH greater than 7
Explanation:
A pH scale is a scale for expressing the level of acidity or alkalinity of aqueous solutions.
This scale is called a pH or pOH scale. The pH is the common one.
pH of a solution is the negative logarithm to base 10 o the hydrogen ion concentration of the solution.
- The scale ranges from 1 through 14.
- An acidic solution has a pH value less than 7. Neutral solutions have pH of 7 and basic solutions have pH greater than 7.
learn more:
acidity brainly.com/question/5121777
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