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In scientific contexts, mass is the amount of "matter" in an object (though "matter" may be difficult to define), whereas weight is the force exerted on an object by gravity.
Answer:
a) W = 6.75 J and b) v = 3.87 m / s
Explanation:
a) In the problem the force is nonlinear and they ask us for work, so we must use it's definition
W = ∫ F. dx
Bold indicates vectors. In a spring the force is applied in the direction of movement, whereby the scalar product is reduced to the ordinary product
W = ∫ F dx
We replace and integrate
W = ∫ (-60 x - 18 x²) dx
W = -60 x²/2 -18 x³/3
Let's evaluate between the integration limits, lower W = 0 for x = -0.50 m, to the upper limit W = W for x = 0 m
W = -30 [0- (-0.50) 2] -6 [0 - (- 0.50) 3]
W = 7.5 - 0.75
W = 6.75 J
b) Work is equal to the variation of kinetic energy
W = ΔK
W = ΔK = ½ m v² -0
v =√ 2W/m
v = √(2 6.75/ 0.90)
v = 3.87 m / s
Answer:
ix chemical elements that comprise Group 2 of the periodic table
Explanation:
Calcium, Magnesium, Barium, Beryllium, Strontium, and Radium are alkaline earth metals.
Mold
Explanation:
A mold is a cavity that is left behind in the rock after an organism hard part has been dissolved. These are important fossils that useful in relative dating.
- Some hard parts of organism are preserved in form of molds in soft sediments.
- The outline and important details of the hard part is preserved when the mold dissolves away.
- Fossil molds are representative on the internal outline of the hard parts of organisms.
- They are usually recognized as a part of body fossil in a section.
learn more:
Fossils brainly.com/question/7382392
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