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
⇒ 

=
+ 

⇒

<h2>QUESTION:- It is easier to lift the same load by using three pulley system than by using two-pulley system.</h2>
<h2>ANSWER:- IN CASE OF IDEAL PULLEY SYSTEM</h2>
<h2>REASON:- </h2>
Logic behind is lies behind the mechanical advantage of the provided bt the Pulley system.
as if we calculate the mechanical advantage of the 2 Pulley system we will have the value 2
And if we will calculate the mechanical advantage of the 3 pulley system then we will get the value of 3
so due to extra mechanical advantage we feel it easy to move with 3 pulley system then 2 Pulley system

Evidence of Chemical Change:
A car rusting
Leaves changing in October
The glow of a light bulb
A white cloudy substance occurs after mixing two substances
Burning toasts
A candle being lit
Evidence of Physical Change:
Water boiling
Yellow and blue paints mixed together
Wax melting
Crushing a rock with a hammer
Hope this helps!
Have a great day!
The correct answer is answer choice C. +1. Since electrons have negative charges, losing one electron will cause the atom to have a positive charge of 1. This charge comes from the protons, which, until one electron was lost, balanced out the negative charge of the electrons and caused the atom to be neutral.