Answer:
Yes
Explanation:
Accerelation is measured by change in velocity. So naturally, if an object is slowing down, its velocity is decreasing so acceleration is negative. If it is speeding up velocity is increasing so positive acceleration.
(Velocity final - Velocity initial)/t
Note that this does not apply only to gravity, but to all linear accelerations
Answer:
Explanation:
Work in pumping water from the tank is given as
W = ∫ y dF. From a to b
Where dF is the differential weight of the thin layer of liquid in the tank, y is the height of the differential layer
a is the lower limit of the height
b is the upper limit of the height.
We know that, .
F = ρVg
Where F is the weight
ρ is the density of water
V is the volume of water in tank
g is the acceleration due to gravity
Then,
dF = ρg ( Ady)
We know that the density and the acceleration due to gravity is constant, also the base area of the tank is constant, only the height that changes.
Then,
ρg = 62.4 lbs/ft³
Area = L×B = 3 × 9 = 27ft²
dF = ρg ( Ady)
dF = 1684.8dy
The height reduces from 12ft to 0ft
Then,
W = ∫ y dF. From a to b
W = ∫ 1684.8y dy From 0 to 12
W = 1684.8y²/2 from 0 to 12
W = 842.4 [y²] from y = 0 to y = 12
W = 842.4 (12²-0²)
W = 121,305.6 lb-ft
Answer:
D) negative, due to extra electrons.
Explanation:
The charge that would be gained will be negative charges due to extra electrons.
Electrons are usually lost or gained by bodies that comes in contact with one another.
They occupy the orbital space in an atom and are not strongly held by forces within the atom.
Protons cannot be lost in such manner. They occupy the nucleus and are bounded by strong chemical forces within it.
The polythene and rods are both made up of chemical substances whose units called atoms are made up of subatomic particles of protons, neutrons and electrons. As with all kinds of matter, there would be pool of free electrons round them that can easily be rubbed off due to the weak attractive forces binding them in the atomic sphere.
When the polythene and rods are rubbed, there would be a loss of electrons and the gaining body, polythene becomes negatively charged.
The word "Everything" belongs in the blank space.
If a substance absorbs energy but its temperature does not change, then the internal potential energy is changing.
