Answer: 539.4 N
Explanation:
Let's begin by explaining that Coulomb's Law establishes the following:
"The electrostatic force
between two point charges
and
is proportional to the product of the charges and inversely proportional to the square of the distance
that separates them, and has the direction of the line that joins them"
What is written above is expressed mathematically as follows:
(1)
Where:
is the electrostatic force
is the Coulomb's constant
and
are the electric charges
is the separation distance between the charges
Then:
(2)
Isolating
and
:
(3)
Now, if we keep the same charges but we decrease the distance to
, (1) is rewritten as:
(4)
Then, the new electrostatic force will be:
(5) As we can see, the electrostatic force is increased when we decrease the distance between the charges.
Answer:

Explanation:
The acceleration of the block can be found by the kinematics equations:

Since the plane is frictionless, the only force acting on the block along the motion of the block is its weight.

You sure wouldn't want something like cm/s or (yikes cm/hr). You want a reasonable number for sports usually between 0 and 100
Km / hour would be a good choice.
The next town to where I live is 25 km away. On a good day, I can make it there in about 3/4 of an hour.
Speed = 25 km / 0.75 hour = 33.3 km/hour. That's actually a little fast most of the time. But you should understand what I mean.
Answer:
C) unbalanced
Explanation:
Equal forces acting in opposite directions are called balanced forces. Balanced forces acting on an object will not change the object's motion. When you add equal forces in opposite direction, the net force is zero.
Answer:
M
Explanation:
To apply the concept of <u>angular momentum conservation</u>, there should be no external torque before and after
As the <u>asteroid is travelling directly towards the center of the Earth</u>, after impact ,it <u>does not impose any torque on earth's rotation,</u> So angular momentum of earth is conserved
⇒
-
is the moment of interia of earth before impact -
is the angular velocity of earth about an axis passing through the center of earth before impact
is moment of interia of earth and asteroid system
is the angular velocity of earth and asteroid system about the same axis
let 
since 

⇒ if time period is to increase by 25%, which is
times, the angular velocity decreases 25% which is
times
therefore

(moment of inertia of solid sphere)
where M is mass of earth
R is radius of earth

(As given asteroid is very small compared to earth, we assume it be a particle compared to earth, therefore by parallel axis theorem we find its moment of inertia with respect to axis)
where
is mass of asteroid
⇒ 

=
+ 

⇒
