Answer:
linear density of the string = 4.46 × 10⁻⁴ kg/m
Explanation:
given,
mass of the string = 31.2 g
length of string = 0.7 m
linear density of the string = 
linear density of the string = 
linear density of the string = 44.57 × 10⁻³ kg/m
linear density of the string = 4.46 × 10⁻⁴ kg/m
Answer:
A ruler.
Explanation:
Just measure height, length and width and multiply each.
Answer:

Explanation:
According to the Coulomb's law, the magnitude of the electrostatic force between two static point charges
and
, separated by a distance
, is given by

where k is the Coulomb's constant.
Initially,

The negative sign is taken with force F because the force is attractive.
Therefore, the initial electrostatic force between the charges is given by

Now, the objects are then brought into contact, so the net charge is shared equally, and then they are returned to their initial positions.
The force is now repulsive, therefore, 
The new charges on the two objects are

The new force is given by

Using (1),



Using (1),
When
,

When
,

Since, 
Therefore, 
Answer:
'A' is the the point on the graph that shows a temperature of 40°C and the time of 25 minutes
Below is the answer. I hope it help.
T ( t ) = C e k t + T m where Tm is the temperature of the surroundings
T ( t ) = C e k t + T m
T ( 0 ) = 20
T ( 1 ) = T ( 0 ) + 2 = 22
C + T m = 20 C+Tm=20
C e k + T m = 22