Potential energy is energy due to an object's height above the ground.
Potential energy = mass x gravity x height
Kinetic energy is energy due to the motion of the object.
Kinetic energy = 1/2 x mass x velocity²
1.
The ball is not moving and is at a height above the ground so it has only potential energy.
P.E = 2 x 9.81 x 40
P.E = 784.8 J
2.
The ball is moving and has a height above the Earth's surface so it has both kinetic and potential energy.
P.E = same as part 1 = 784.8 J
K.E = 1/2 x 2 x 5²
K.E = 25 J
3.
The ball has no height above the Earth's surface and is moving so it has only kinetic energy.
K.E = 1/2 x 2 x 10²
K.E = 100 J
4.
50000 = 1/2 x 1000 x v²
v = 10 m/s
5.
39200 = 200 x 9.81 x h
h = 20.0 m
6.
12.5 = 1/2 x 1 x v²
v = 5 m/s
98 = 1 x 9.81 x h
h = 10.0 m
Empirical formula is the simplest ratio of whole numbers of components in a compound.
Assuming for 100 g of the compound
Cu As S
mass 48.41 g 19.02 g 32.57 g
number of moles 48.41 / 63.5 g/mol 19.02 / 75 g/mol 32.57 / 32 g/mol
= 0.762 mol = 0.2536 mol = 1.018 mol
divide by the least number of moles
0.762 / 0.2536 0.2536 / 0.2536 1.018 / 0.2536
= 3.00 = 1.00 = 4.01
once they are rounded off
Cu - 3
As - 1
S - 4
therefore empirical formula is Cu₃AsS₄
2-bromo-1-chloro-4-nitrobenzene is being synthesized in following sequence:
Step 1: Chlorination of Benzene:
This is Halogenation reaction of benzene. In this step benzene is reacted with Chlorine gas in the presence of lewis acid (i.e. FeCl₃). This results in the formation of Chlorobenzene as shown in red step below.
Step 2: Nitration of Chlorobenzene:
The chlorine atom on benzene has a ortho para directing effect. Therefore, the nitration of chlorobenzene will yield para nitro chlorobenzene as shown in blue step below.
Step 3: Bromination of 1-chloro-4-nitrobenzene:
In this step bromination is done by reacting bromine in the presence of lewis acid. The chlorine being ortho para directing in nature and nitro group being meta directing in nature will direct the incoming Br⁺ (electrophile) to the desired location. Hence, 2-bromo-1-chloro-4-nitrobenzene is synthesized in good yield.
Answer:
Ea=5.5 Kcal/mole
Explanation:
Let rate constant are
and
at temperature
and 
By using Arrhenius equation at two different two different temperature,
By putting value of R=2 cal/mole.K

By rounding off upto 2 significant figure;
