Answer:
60000 J
Explanation:
Assuming the force is applied parallel to the displacement of the elephant, the work done to move it across the floor is

where
F = 2000 N is the force applied
d = 30 m is the displacement of the elephant
Substituting the numbers into the formula, we find

Density is defined as [mass] / [volume] .
The only choice listed with those physical dimensions is 'd' .
Answer:
2.9 M
Explanation:
The concentration-time equation for a second order reaction is:
1/[A] = kt + 1/[A°]
Where,
A = concentration remaining at time, t
A° = initial concentration
k = rate constant
1/[A] = (1.80 x 10^-3) * (45.6) + 1/3.81
1/[A] = 0.345
= 1/0.345
= 2.9 M.
Answer:
Gallium
Explanation:
Gallium is one such element used as a do/pant in a p-type semiconductor.
A do/pant is an impurity added to a semi-conductor used to alter its properties. Semi-conductors have a wide range of applications. They will conduct heat and electricity only under certain conditions. This property is highly desirable and find a wide application in electronics.
For p-type conductors, they are best do/ped with elements with 3 valence electrons. These are group 3 elements. From the choices, only gallium belongs to this group.
Other elements given are good do/pants for n-type semiconductors. They have 5 valence electrons.