Hi!
The energy of the block is 4 m/s
To calculate this, you need to use the equation for
kinetic energy. The block is sliding (i.e. it's moving). If the object is sliding across a level surface, the only energy it has is kinetic energy, because
there is no change in potential energy (which changes with height). So, the mechanical energy will be pure kinetic energy. The equation is the following, derived from the expression for kinetic energy:

Have a nice day!
Answer:
0.2 T
Explanation:
Magnetic field is inversely proportional to the distance from wire since the distance is halved therefore magnetic field will be doubled.
Explanation:
Fe₂O₃ + CO → Fe₃O₄ + CO₂
Balancing the equation above, we can derive simple mathematical equations that are very easy to solve.
aFe₂O₃ + bCO → cFe₃O₄ + dCO₂
a,b,c and d are the coefficients needed to balance the equation above;
Conserving Fe; 2a = 3c
O: 3a + b = 4c + 2d
C: b = d
let a = 1;
c = 
Since b = d
3a + d = 4c + 2d
3a = 4c + 2d - d
3a = 4c + d
a = 1, c = 
3 = 4 x
+ d
d = 
b = 
multiplying a, b, c and d by 3:
a = 3 b = 1 c = 2 and d = 1
3Fe₂O₃ + CO → 2Fe₃O₄ + CO₂
Learn more:
Balanced equation brainly.com/question/2612756
#learnwithBrainly
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Sound wave needs medium to travel
as energy which travels in this wave is because of transfer from one particle to another particle
If there is no medium then energy can not be transferred and sound wave will not travel
so in vacuum we can not listen sound
similarly here air is removed it means there is no medium inside the jar to travel the sound and hence we can not hear it
Option B is correct
Without air, the sound waves cannot travel to the ear.
Answer:
t = 444.125 sec
Explanation:
Given data:
V = 24 volt
I = 0.1 ampere
mass of water mw = 51 gm
cr = 4.18 J/gm degree K^-1
mass of resistor = 8 gm
cr = 3.7 J/gm degree K^-1
we know that power is given as
Power P = VI
But P =E/t
so equating both side we have

solving for t


t = 444.125 sec