1) See attached figure
The relationship between charge and current is:
where
i is the current
Q is the charge
t is the time
Therefore, the current is the rate of change of the charge passing through a given point over time.
This means that for a graph of charge over time, the current is just equal to the slope of the graph.
For the graph in this problem:
- Between t = 0 and t = 2 s, the slope is
therefore the current is
i = 25 A
- Between t = 2 s and t = 6 s, the slope is
therefore the current is
i = -25 A
- Between t = 6 s and t = 8 s, the slope is
therefore the current is
i = 25 A
The figure attached show these values plotted on a graph.
2) 
The previous equation can be rewritten as
This equation is valid if the current is constant: if the current is not constant, then the total charge is simply equal to the area under a current vs time graph.
Here we have the current vs time graph, so we gave to find the area under it.
The area of the first triangle is:
While the area of the second square is
So, the total area (and the total charge) is
Answer:
4.3 m/sec
Explanation:
Here height of cliff = y = 37.6 m
Gravitational acceleration = g = 9.8 m/sec2
vi = 0 m/s
Let's find the time which the diver will take if jumps from there!
Using formula
y = vit+1/2gt2
==> 37.6= 0 + 0.5 ×9.8×
==>= 
==> t = 2.8 sec
In this time the diver has to cover a horizontal distance of 12.12 m
If x = 12.12 m is the horizontal distance to be covered then using
x= Vx × t
==> Vx = x/t
==> Vx= 12.12/2.8 = 4.3 m/s
Should be 250m. check with your teacher and let me know
Answer:
A. chemical substance whose atoms all have the same number of protons
Explanation:
An element is a substance which contains identical atoms that have the same number of protons in the nucleus.
Elements are arranged in the periodic table according to their atomic number (= number of protons): so atoms of different elements have a different number of protons in their nuclei.
For a neutral atom, the number of electrons around the nucleus is also equal to the number of protons.
Moreover, atoms of the same element can have a different number of neutrons, despite having the same number of protons - these atoms are called isotopes.
