The answer is c or d mainly d
Water has a higher specific heat so it requires more energy to heat than sand.
Answer:
or -0.000250 C
Explanation:
The field points downward, which is the direction of a positive charge. In order for the penny to rise, it has to have a negative charge since its direction is opposite that of the field.
To calculate the magnitude of the charge:
The penny is to accelerate upward so it must overcome gravity. Hence, the net force to cause it to accelerate it upward is the difference between the electrostatic force and its weight.






Now, the electric field intensity is given by

where q = charge

to 3 significant figures.
In standard form, q =
The negative sign indicates it has a negative charge, as explained initially.
We can use the equation of state for an ideal gas to answer the question:

or, by rewriting it,

where p is the gas pressure, V its volume, T its temperature, n the number of moles of the gas and R the gas constant.
When the gas is sprayed from the can into the room, its volume V has increased, while n (the number of moles of the gas) stayed the same. Since R is a constant and the temperature T also stayed constant, if we look at the formula we see that the numerator didn't change, while the denominator (V) has increased, so the pressure of the gas has decreased.