Anions: negatively charged atoms
Cations: positively charged atoms (CAT-ions are PAWS-itively charged)
Anode: positively charged electrode that allows electrical current flow (positive end of battery)
Cathode: negatively charged electrode that allows electrical current flow (negative end of batter)
Answer: Electric field vector is created by an electric force of a charged particle.
Explanation: The direction of the field vector can be determined by applying Coulomb’s Law which explains the electric force between charge particles. If q is positive the force is repulsive, to a test charge ( which is positive always ) and if q is negative the force is attractive to a test charge.
Area=side^2=4^2=16cm^2=0.0016m^2
Answer:
R₁ = (n -1) f
Explanation:
In geometric optics the focal length and the radius of curvature are related, for the case of a lens
1 / f = (n₂-n₀) (1 / R₁ - 1 / R₂)
where f is the focal length, n₂ is the refractive index of the material, n₀ is the refractive index of the medium surrounding the material, R₁ and R₂ are the radius of curvature of each of the material's
In our case, the most common is that the lens is in the air, so n1 = 1, in many cases one of the surfaces is flat, so its radius of curvature R₂ = ∞.
1 / f = (n-1) (1 / R₁)
we look for the radius of curvature R₁
1 / R₁ = 1 / f (n-1)
R₁ = (n -1) f
With this expression we can find the radius of curvature of a concave-plane lens
There is a 40m drop from the bridge, so we can work out the time of the vertical component first (how long it will take to reach the water)
do this by using a SUVAT equation s=ut+0.5at^2
this rearranges to t= sqrt(2s/a)
- note that u has been removed since there is no initial velocity.
sqrt((2*40)/9.81)= 2.86 seconds
this means that the horizontal component of 50m has so be covered in 2.86s
and speed = distance/ time
50m/2.86s=17.48ms^-1
the line has to be thrown at 17.48ms^-1 or more to reach the life boat.
