Answer:
D) 11 m/s
Explanation:
The problem asks us to calculate the velocity of the hot dog with respect to the observer stationary outside the train. This velocity is given by:

where
is the velocity of the train (towards right)
is the velocity of the man (towards right)
is the velocity of the hot-dog (towards left, so we put a negative sign)
Substituting the numbers into the equation, we find

and the positive sign means the velocity is toward right.
It's a quantitative observation because it includes numerical data.
Answer:
Earth's crust is covered by a densed air blanket called atmosphere. Due to which we feel warm even during night when there is no sun. The air near the atmosphere is less dense compared to the air near our crust. Similarly we can experience high pressure near the atmosphere comparelatively we experience less pressure near crust. The presence of atmosphere above us makes the wind fair sometimes stromy and also helps in pteperation of wind and breezes in earth's surface.
Explanation:
Electronegativity is the property of an atom that attracts the shared pair of an electron to itself. There is a trend in the periodic table.
While moving down in a group, the electronegativity decreases. This is due to the reason that as we move down the number of shells added and so the electron become very far from the pull of the nucleus.
As we move across a period the electronegativity increases. This is because of the no. of charge on the nucleus increase.