Answer:
2m/s²
Explanation:
velocity = displacement (distance in a specified direction /time
Answer:
Part a)

Part b)

Part c)

Explanation:
Part a)
As we know that the friction force on two boxes is given as



Now we know by Newton's II law

so we have




Part b)
For block B we know that net force on it will push it forward with same acceleration so we have




Part c)
If Alex push from other side then also the acceleration will be same
So for box B we can say that Net force is given as




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, 
Wavelength = wavespeed / frequency
0.5 meter = speed / 200 Hz
speed = 0.5m * 200 Hz
= 100 m/s
Solved
Power dissipated across any resistance is given by

now it is given that when one resistance of value 3 ohm connected the power dissipated is 4 Watt
now another identical resistance of same value is connected then the current will reduce to half of its initial value.
now power across any one resistance is given by

So now we will have

So now the power will become 1/4 times of initial power
So now the power will be
