Answer:
30.5 x 10³ min.
Explanation:
Atomic weight of aluminium = 27
For the reaction
Al⁺³ + 3e = Al
3 mole of electron is required by 1 mole of aluminium
3 x 96500 C of charge is required for 27 gram of aluminium
60.2 g aluminium will require

645.47 x 10³ C
So charge required = 645.47 x 10³ C
Now Charge = Current x time
Current ( given ) = 0.352A
Time = charge / current = 645.47 x 10³ / .352
=1833 x 10³ s
30.5 x 10³ minutes
It takes twice the force to produce the same acceleration in the 2kg rock.
Answer:
The equation that will relate all the given parameters, in other to calculate the potential energy of charge A is:
∆V = ∆U/q, ∆V is potential at charge A position, q is magnitude of charge A, ∆U will be made the subject of the relation, which is the Potential Energy of charge A. The notation "∆" show, the quantities have both in values and final values, in the electric field.(Change in Electric potential and potential energy, due to the effect of the field)
Explanation:
The potential energy of a charged particle (Charge A) in an electric field depends on the magnitude of the charge(Known as stated in the question). However, the potential energy per unit charge has a unique value at any point in the electric field.
Given that,
Mass of each washer = 4.9 g
We need to calculate the mass of two washers in kg
Using conversion of unit
Mass of each washer 
So, Mass of two washers is

Put the value of m


If 4 washer are attached to the spring
We need to calculate the applied force on the car
Using formula of force

Put the value into the formula


Hence, (i), The mass of two washers is 0.0098 kg.
(ii). The applied force on the car is 0.192 N.