Explanation:
We have,
Surface area, 
The current varies wrt time t as :

(a) At t = 2 seconds, electrical charge is given by :

(b) Current is given by :

Instantaneous current at t = 1 s is,

(c) Current is, 
Current density is given by electric current per unit area.

Therefore, it is the required explanation.
Answer:
Time taken to reach the tree
they have given the maximum height which is 25m
therefore...
v=u+at (upward)
0 = 45sin(20)-9.81t
t = 1.56s
If the group of all forces acting on an object is balanced,
then the effect of all of them is the same as if there were
no forces at all on the object. In that case, the object
continues moving in a straight line at a constant speed.
1 . W=mass times acceleration due to gravity
60kg times 9.8m/s2
= 588N
2. W=mg
1176N=m times 9.8
m=120kg
3. 1 hour=3600s
24 hours=?
24 times 3600
= 86400 seconds
4. 1000g=1kg
25000g=?
25000 times 1 divide by 1000
=25kg
5. 1000000mg=1kg
123000000=?
123000000 times 1 divide by 1000000
=123 kg