Answer:
Potential
Explanation:
The most accurate term is Electrostatic potential energy
It's named like this because the force between charges or electrons is called electrostatic force .
Solid elements are rigid elements. For example an element iron is in solid form. You can touch it and it’s hard.
Answer:
Acceleration of the car will be 
Explanation:
We have given that car starts from rest so initial velocity of the car u = 0 m/sec
And car traveled 400 m in 10 sec
So distance traveled by car s = 400 m
Time taken to compete this distance t = 10 sec
We have to find the acceleration of the car
From second equation of motion we know that 
So 

So acceleration of the car will be 
Answer: The force needed is 140.22 Newtons.
Explanation:
The key assumption in this problem is that the acceleration is constant along the path of the barrel bringing the pellet from velocity 0 to 155 m/s. This means the velocity is linearly increasing in time.
The force exerted on the pellet is
F = m a
In order to calculate the acceleration, given the displacement d,

we will need to determine the time t it took for the pellet to make the distance through the barrel of 0.6m. That time can be determined using the average velocity of the pellet while traveling through the barrel. Since the velocity is a linear function of time, as mentioned above, the average is easy to calculate as:

This value can be used to determine the time for the pellet through the barrel:

Finally, we can use the above to calculate the force:
