Answer:
4.2 J
Explanation:
Specific heat capacity: This is defined as the amount of a heat required to rise a unit mass of a substance through a temperature of 1 K
From specific heat capacity,
Q = cmΔt.............................. Equation 1
Where Q = amount of energy absorbed or lost, c = specific heat capacity of water, m = mass of water, Δt = Temperature rise.
Given: m = 1 g = 0.001 kg, Δt = 1 °C
Constant : c = 4200 J/kg.°C
Substitute into equation 1
Q = 0.001×4200(1)
Q = 4.2 J.
Hence the energy absorbed or lost = 4.2 J
The correct answer is A. Acid rain forms from human activities and lowers the pH of rainwater below 7
Explanation:
The term "acid rain" is used to refer to rainwater with a low pH or a high acidity, this includes rainwater with a pH below 7 (solutions with a pH under 7 are acidic). In terms of formation, acid rain is mainly the result of human activities such as factories or cars that release pollutants into the atmosphere including nitric and sulfuric acids and these alter the natural pH of rain and makes it more acidic. Additionally, acid rain has negative consequences such as the death of fishes and other organisms in lakes, rivers, etc. because the acidity is toxic to many organisms. Thus, acid rain is the result of human activities and it lowers the pH of rain (Option A).
Answer:
Friction is useful in some cases like walking and cycling ..
but it is unwanted in machines as it create unwanted sounds and heat .,due to which we loss energy
Explanation:
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The characteristics of the velocity vector used to find the results for the direction of acceleration and velocity are:
- Acceleration is towards the center of the circle
- The velocity is tangent to the circle counterclockwise.
Newton's Second Law establishes a relationship between force, mass and acceleration of bodies.
<h3>Centripetal acceleration.
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In the case of circular motion there is a constant change in the direction of the velocity vector, even when its module remains constant, this change in direction points towards the center of the circle, so that the module is constant.
They indicate that the satellite is moving counterclockwise, therefore the speed must go to the left (counterclockwise) tangential to the circle.
In conclusion using the characteristics of the velocity vector we can find the results for the direction of acceleration and velocity are:
- Acceleration is towards the center of the circle
- The velocity is tangent to the circle counterclockwise.
Learn more about centripetal acceleration here: brainly.com/question/25243603
