Answer:
The mass of the child + skateboard is 50 kg
Explanation:
In this problem, we can apply Newton's second law:
F = ma
where
F is the net force on a system
m is the mass of the system
a is the acceleration of the system
In this problem, our system is the child + the skateboard. The net force on them is
F = 75 N
and their acceleration is

So we can re-arrange the equation above to find their combined mass:

200g*1 mole/ 18g=11.1 moles There are 11.1 moles of water.
Answer:
v = 6.95 m/s
Explanation:
Given that,
A diver is on a board 1.80 m above the water, s = 1.8 m
The initial speed of the diver, u = 3.62 m/s
Let v is the speed with which she hit the water. It will move under the action of gravity. Using the equation of motion as follows :

So, she will hit the water with a speed of 6.95 m/s.
<h2>Answer:</h2><h3>(A) the positively charged surface increases and the energy stored in the capacitor increases.</h3>
When charging a capacitor transferring charge from one surface to the other, the first surface becomes negatively charged while the second surface becomes positively charged. As you transfer the charge, the voltage of the positively charged surface increases and the energy stored in the capacitor also increases. We can solve this by the definition of <em>capacitance</em><em> </em>that is <em>a measure of the ability of a capacitor to store energy. </em>For any capacitor, the capacitance is a constant defined as:

To maintain
constant, if Q increases V also increases.
On the other hand, the potential energy
can be expressed as:

In conclusion, as Q increases the potential energy also increases.