D. There are two phosphate ions in a molecule of magnesium phosphate
Answer:
Approximately
assuming no heat exchange between the mixture and the surroundings.
Explanation:
Consider an object of specific heat capacity
and mass
. Increasing the temperature of this object by
would require
.
Look up the specific heat of water:
.
It is given that the mass of the water in this mixture is
.
Temperature change of the water:
.
Thus, the water in this mixture would have absorbed :
.
Thus, the energy that water absorbed was:
.
Assuming that there was no heat exchange between the mixture and its surroundings. The energy that the water in this mixture absorbed,
, would be the opposite of the energy that the metal in this mixture released.
Thus:
(negative because the metal in this mixture released energy rather than absorbing energy.)
Mass of the metal in this mixture:
.
Temperature change of the metal in this mixture:
.
Rearrange the equation
to obtain an expression for the specific heat capacity:
. The (average) specific heat capacity of the metal pieces in this mixture would be:
.
Displacement is usually given to you as it is, but you can also get displacement through velocity by Δd= Δv*t, where <span>Δv is the change in velocity and t is the change in time.
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Answer:
500 N
Explanation:
Because even if he lift one foot his weight will be same as the pressure applied on the scale will be the same and will not change it is not that the scale measures each foot separately
Answer:
D) No, because of the way work is defined
Explanation:
The work done on an object is given by:

where
F is the force applied on the object
d is the displacement of the object
is the angle between the direction of the force and the displacement
From the formula, we observe that if there is no motion involved, then the displacement of the object is zero:
d = 0
As a result, the product in the formula is also zero, therefore the work done will be zero as well.