Turn off lights when leaving rooms.
Unplug unused appliances. Even when powered off these appliances use electricity.
Replace regular light bulbs with energy saving bulbs.
Answer:
4 m/s
Explanation:
Momentum is defined as:

where
m is the mass of the object
v is its velocity
For the object in this problem, we know:
p = 200 kg m/s is the momentum
m = 50 kg is the mass
Solving for the velocity, we find:

Answer:
The correct answer is A. Vibration.
Explanation:
Mechanical waves is formed by the oscillation of matter and therefore transfer energy from one medium to the other. Unlike electromagnetic waves, mechanical waves need some medium to propagate. It requires an initial energy input and thus carries this energy when it propagates. There are three types of mechanical waves namely transverse waves, longitudinal waves and surface waves. Examples of such waves are sound waves, water waves and seismic waves.
Answer:
Following are the solution to this question:
Explanation:
Law:




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
⇒ 

=
+ 

⇒
