Answer:
Direct current is used in any electronic device with a battery for a power source. It is also used to charge batteries, so rechargeable devices like laptops and cell phones
Explanation:
Answer: The spring constant is K=392.4N/m
Explanation:
According to hook's law the applied force F will be directly proportional to the extension e produced provided the spring is not distorted
The force F=ke
Where k=spring constant
e= Extention produced
h=2m
Given that
e=20cm to meter 20/100= 0.2m
m=100g to kg m=100/1000= 0.1kg
But F=mg
Ignoring air resistance
assuming g=9.81m/s²
Since the compression causes the plastic ball to poses potential energy hence energy stored in the spring
E=1/2ke²=mgh
Substituting our values to find k
First we make k subject of formula
k=2mgh/e²
k=2*0.1*9.81*2/0.1²
K=3.921/0.01
K=392.4N/m
Answer:
a) 
, b) 
, c) 
Explanation:
a) The capacitance of two parallel plates capacitor with dielectric is given by the following expression:
Where:
- Dielectric constant.
- Vaccum permitivity.
- Plate area.
- Distance between plates.
Hence, the capacitance of the system is:
b) The charge can be found by using the definition of capacitance:
c) The energy stored in the charged capacitor is:
Where Gravity rely's on only mass and distance and nothing else, so the weight on the planets will vary like you have stated. However Mars is smaller than Mercury, so the weight on Mars will be less, and the weight on Mercury will be more. Think this way.
More Mass = More Gravity = More Weight
Less Mass = Less Gravity = Less Weight
