Answer:
C.
Explanation:
Option C
The information given in the question tells us about the number of electrons in an atom and also the number of shells in the atom. So, we will come to know about the atomic number, size and chemical properties of the atom. But we cannot determine atomic mass. Atomic mass is a function of number of neutrons and protons.
Answer:
Speed of the speeder will be 28 m/sec
Explanation:
In first case police car is traveling with a speed of 90 km/hr
We can change 90 km/hr in m/sec
So 
Car is traveling for 1 sec with a constant speed so distance traveled in 1 sec = 25×1 = 25 m
After that car is accelerating with
for 7 sec
So distance traveled by car in these 7 sec

So total distance traveled by police car = 224 m
This distance is also same for speeder
Now let speeder is moving with constant velocity v
so 
v = 28 m/sec
Answer:
Explanation:
Given
length of wire 
change in length 
mass of wire 
Young's modulus for silver 
load on wire 

change in length is given by

Where A=area of cross-section




also wire is the shape of cylinder so cross-section is given by





The answer is b
300,000 km
Answer: Option (B) is the correct answer.
Explanation:
A process in which transfer of heat occurring when one object touches another object is known as conduction.
For example, when a pan is heated and then an egg is placed over the pan. Then there will be transfer of heat from pan towards the egg.
As a result, the egg gets cooked because the egg was touching the pan.
Hence, we can conclude that it is conduction because the egg is touching the pan.