The question is missing, however, I guess the problem is asking for the value of the force acting between the two balls.
The Coulomb force between the two balls is:
where
is the Coulomb's constant,
is the intensity of the two charges, and
is the distance between them.
Substituting these numbers into the equation, we get
The force is repulsive, because the charges have same sign and so they repel each other.
To solve this problem we use the general kinetic equations.
We need to know the time it takes for the car to reach 130 meters.
In this way we have to:
Where
= initial position
= initial velocity
= acceleration
= time
= position as a function of time
.
We use the quadratic formula to solve the equation.
t = 6.63 s and t = -17.1 s
We take the positive solution. This means that the car takes 6.63 s to reach 130 meters.
Then we use the following equation to find the final velocity:
Where:
= final speed
The final speed of the car is 27.25 m/s
Answer:
A force has both magnitude and direction, therefore: Force is a vector quantity; its units are newtons, N. Forces can cause motion; alternatively forces can act to keep (an) object(s) at rest. ... Consider two forces of magnitudes 5 N and 7 N acting on a particle, with an angle of 90◦ between them.
Explanation:
from google
If an icy surface means no friction, then Newton's second law tells us the net forces on either block are
• <em>m</em> = 1 kg:
∑ <em>F</em> (parallel) = <em>mg</em> sin(45°) - <em>T</em> = <em>ma</em> … … … [1]
∑ <em>F</em> (perpendicular) = <em>n</em> - <em>mg</em> cos(45°) = 0
Notice that we're taking down-the-slope to be positive direction parallel to the surface.
• <em>m</em> = 0.4 kg:
∑ <em>F</em> (vertical) = <em>T</em> - <em>mg</em> = <em>ma</em> … … … [2]
<em />
Adding equations [1] and [2] eliminates <em>T</em>, so that
((1 kg) <em>g</em> sin(45°) - <em>T </em>) + (<em>T</em> - (0.4 kg) <em>g</em>) = (1 kg + 0.4 kg) <em>a</em>
(1 kg) <em>g</em> sin(45°) - (0.4 kg) <em>g</em> = (1.4 kg) <em>a</em>
==> <em>a</em> ≈ 2.15 m/s²
The fact that <em>a</em> is positive indicates that the 1-kg block is moving down the slope. We already found the acceleration is <em>a</em> ≈ 2.15 m/s², which means the net force on the block would be ∑ <em>F</em> = <em>ma</em> ≈ (1 kg) (2.15 m/s²) = 2.15 N directed down the slope.
