Answer:
D).happens when soil is weakened by water and seismic waves
Explanation:
Liquefaction is a phenomenon in which the strength of the soil weakens due to the earthquake or any other load. The solid behaves like a liquid. Liquefaction of soil below structures cause lot of damage during Earthquakes.The soil looses stiffness due to seismic waves and water.
Thus, the correct option is D.
Answer:
The gravity, which is an acceleration to the center of the earth, will be the same.
Explanation:
The gravity on earth depends only on the masses and distance, between two objects. We can see it in the gravitational force equation.
Now if we put a man, with mass m, on the surface of the earth, with mass M, the distance from the center of mass and the man will be R (earth radius). Knowing that F = m*a, we can find the accelerations due to this mass M and this value will be 9.81 m/s².
On the other hand, the moon has a gravity value and is less than the earth, because its mass, and affects the water sea due to the gravitational force between earth and moon. If the moon changes the rate of its rotate it changes probably the distance between them, let's recall they must conserve angular momentum, but the gravity won't be affected.
Therefore, the gravity, which is an acceleration to the center of the earth, will be the same.
I hope it helps you!
We have that F=ma from the 2nd Newton law where F is the force, m is the mass and a is the acceleration. Suppose we have that F' is the new force and m' is the new mass. Then, we have that a'=F'/m' still, by rearranging Newton's law. We are given that F'=2F and m'=m/2. Hence,

But now, we have from F=ma, that a=F/m and we are given that a=1m/s^2.
We can substitute thus, a'=4a=4*1m/s^2=4m/s^2.
Answer:
the number of additional car lengths approximately it takes the sleepy driver to stop compared to the alert driver is 15
Explanation:
Given that;
speed of car V = 120 km/h = 33.3333 m/s
Reaction time of an alert driver = 0.8 sec
Reaction time of an alert driver = 3 sec
extra time taken by sleepy driver over an alert driver = 3 - 0.8 = 2.2 sec
now, extra distance that car will travel in case of sleepy driver will be'
S_d = V × 2.2 sec
S_d = 33.3333 m/s × 2.2 sec
S_d = 73.3333 m
hence, number of car of additional car length n will be;
n = S_n / car length
n = 73.3333 m / 5m
n = 14.666 ≈ 15
Therefore, the number of additional car lengths approximately it takes the sleepy driver to stop compared to the alert driver is 15
Question 8
Silicon is a semi-conductor that are mostly used in electronic devices. From the choices give, silicon is applicable in t<span>ransistor, integrated circuit and diode. But the best answer that suits this question is (B) integrated circuit.
Question 9
Power is the rate of doing work. It is calculated as,
Power = workdone/time taken to do that work.
In electricity, power = current </span>×voltage
From ohm's law, V=IR
Where I⇒current and
R⇒ resistance.
∴Power = I²R
= 6²×5
= 180 Watts