Answer:
-2
Explanation:
Since its a compound, it's charge is 0.
So, there are 2 Fe and 3 Oxygen,
let x = oxidation number of oxygen
2(+3) + 3x =0
x =-2
Side note : even if the oxidation number is positive, make sure to put the positive sign like how you would in numbers
Answer:In first case
Explanation:
When two People pull the spring, let the applied force by each person be 
and spring constant of spring be k
so Total force is 
total extension according to Hooke's law is
When they detach the spring and apply force in opposite direction then force on either side is F so net extension is
so in first case there will be more extension
Answer:
Explanation:
the momentum of a body is defined as the product of mass of body and the velocity f the body.
P = m x v
Where, m is the mass and v be the velocity of the body.
it is a vector quantity and its unit is newton second.
When the velocity of the object is zero, the momentum is also zero.
Newtons' first law states that the body is at rest or in motion , it remains at rest or in motion until and unless an external force is not applied on the body.
So, When a body is at rest it remains at rest.
<span>m1 = 5g = 0.005kg
v1 = 0
m2 = 1.0 x 10^-7g = 1.0x10^-10kg
v2 = 7.5
v3 = ?
looks like you did the formula correctly
m1v1 + m2v2 = (m1+m2)v3
0 + m2v2 = (m1+m2)v3
m2v2 / (m1+m2) = v3
(1.0x10^-10)(7.5) / (0.005 + 1.0x10^-10) = v3
1.5x10^-7 = v3
However, it said the bee gets hit by 1000 pollen grains, so I would guess you have to multiply 1.0 x 10^-10 by 1000 first, unless the total mass of the 1000 grains really is 1.0 x 10^-10.</span>
