Answer:

where E = electric field intensity
Explanation:
As we know that plastic ball is suspended by a string which makes 30 degree angle with the vertical
So here force due to electrostatic force on the charged ball is in horizontal direction along the direction of electric field
while weight of the ball is vertically downwards
so here we have


since string makes 30 degree angle with the vertical so we will have





where E = electric field intensity
Answer:
Q1: 3.2km
Q2: 4.8K
Explanation:
Q1:
So db is the distance of bird, and dr is the distance of runner
db = 2vr and the distance of bird is going to be 2 times greater than the runner.
formulas: db = 2vr & db = 2dr
- db = 2dr
- L + (L - x) = 2x
- 2L - x = 2x
- 2L = 3x
- x =
L
Insert it in x =
L
(2.4km) = 1.6km
Now we use formula db = 2dr
- db = 2L - x
- db = 2(2.4km) - 1.6km
- <u>db = 3.2km</u>
Q2:
Formulas: Vr = L /Δt & Vb = db/Δt
- Vr = L/ Δt ⇒ Δt =



(Km cancel each other)
- Vb = db/Δt ⇒ db = VbΔt
- 13.6km/hr

- <u>4.8km</u>
(hr cancel each other)
Hope it helps you :)
Answer: The correct answer is option (B).
Explanation:
Law of conservation of mass: 'In a chemical reaction, mass neither be created nor be destroyed'
In the balance chemical equation,total mass of the reactants is equal to the total mass of the products.
A. 
![[2\times (23 g/mol)+(35.5 g/mol)\times 2]=[23 g/mol+35.5 g/mol]](https://tex.z-dn.net/?f=%5B2%5Ctimes%20%2823%20g%2Fmol%29%2B%2835.5%20g%2Fmol%29%5Ctimes%202%5D%3D%5B23%20g%2Fmol%2B35.5%20g%2Fmol%5D)
117 g/mol ≠ 58.5 g/mol
Law of Conservation of Mass not followed.
B.
![[2\times (23 g/mol)+(35.5 g/mol)\times 2]=2\times [23 g/mol+35.5 g/mol]](https://tex.z-dn.net/?f=%5B2%5Ctimes%20%2823%20g%2Fmol%29%2B%2835.5%20g%2Fmol%29%5Ctimes%202%5D%3D2%5Ctimes%20%5B23%20g%2Fmol%2B35.5%20g%2Fmol%5D)
117 g/mol = 117 g/mol
Law of Conservation of Mass is followed.
C.
![[2\times (23 g/mol)+(35.5 g/mol)\times 2]=2\times [23 g/mol+35.5 g/mol]](https://tex.z-dn.net/?f=%5B2%5Ctimes%20%2823%20g%2Fmol%29%2B%2835.5%20g%2Fmol%29%5Ctimes%202%5D%3D2%5Ctimes%20%5B23%20g%2Fmol%2B35.5%20g%2Fmol%5D)
188 g/mol ≠ 117 g/mol
Law of Conservation of Mass not followed.
D.
![[(23 g/mol)+(35.5 g/mol)\times 2]=2\times [23 g/mol+35.5 g/mol]](https://tex.z-dn.net/?f=%5B%2823%20g%2Fmol%29%2B%2835.5%20g%2Fmol%29%5Ctimes%202%5D%3D2%5Ctimes%20%5B23%20g%2Fmol%2B35.5%20g%2Fmol%5D)
94 g/mol ≠ 117 g/mol
Law of Conservation of Mass not followed.
Hence, the correct answer is option (B).
Answer:

Given:
Radius of ball bearing (r) = 1.5 mm = 0.15 cm
Density of iron (ρ) = 7.85 g/cm³
Density of glycerine (σ) = 1.25 g/cm³
Terminal velocity (v) = 2.25 cm/s
Acceleration due to gravity (g) = 980.6 cm/s²
To Find:
Viscosity of glycerine (
)
Explanation:


Substituting values of r, ρ, σ, v & g in the equation:






The heavy stone would produce waves with a higher amplitude, rather than the smaller stone, because since the stone is heaver its going to have a grater impact and displace more water to create a bigger wave.