Answer:
Electron
Explanation:
An object can become electrically charged when it gains or loses an electron. Because an electron is negatively charged, when an object gains an electron it becomes negatively charged. Also, when it gives up an electron, it becomes positively charged. This positive charge is because the atom has one proton more than electron. In a neutral atom, the number of the proton is equal to the number of the electron. An electron is negatively charged, and a proton is positively charged.
A single prolonged blast emitted by a boat using an efficient sound producing devices indicates that the boat is leaving the dock. It may also be used to indicate that the boat is moving and for alarming other vessels, but in this case, one prolonged blast is followed by two short blasts, in two minutes of time.
Answer:
Speed, Vfx = 7.619 m/s
Explanation:
Vertical distance, Dx = 5.4m
Horizontal distance, Dy = 8m
Acceleration due to gravity, g = 9.8m/s²
Initial speed, Vix = 0m/s²
To find the speed, we would use the second equation of motion to find the time, t;
Dx = Vixt + ½gt²
Substituting into the equation, we have;
5.4 = 0(t) + ½(9.8)*t²
5.4 = 0 + 4.9t²
Rearranging the equation, we have;
4.9t² = 5.4
t² = 5.4/4.9
t² = 1.1020
Taking the square root of both sides;
t = 1.050 secs.
For the speed;
Dy = Vfxt
Vfx = Dy/t
Vfx = 8/1.050
Vfx = 7.619 m/s
<em>Therefore, the speed of the pelican is 7.619 m/s</em>
Answer:
The weight of the girl = 1045.86 kg/m³
Explanation:
Density: This can be defined as the ratio of the mass of a body to the volume of that body. The S.I unit of density is kg/m³.
From Archimedes principle,
R.d = Density of the person/Density of water = Weight of the person in air/Upthrust.
⇒ D₁/D₂ = W/U............................... Equation 1.
Where D₁ = Density of the person, D₂ = Density of water, W = Weight of the person in air, U = Upthrust in water.
Making D₁ the subject of the equation,
D₁ = D₂(W/U)................................... Equation 2
<em>Given: D₂ = 1000 kg/m³ , W = 509.45 N, U = lost in weight = weight in air - weight in water = 509.45 - 22.34 = 487.11 N</em>
<em>Substituting these values into equation 2</em>
D₁ = 1000(509.45/487.11)
D₁ = 1045.86 kg/m³
Thus the weight of the girl = 1045.86 kg/m³
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