There are six alkaline earth metals. They are found in column 2 in the Periodic Table. They have the following properties: they are very reactive, are not found freely in nature. high boiling and melting points, low density, two electrons in the outer shell..The are most likely to be combined (to react) with the oxygen. Reacting with the oxygen the alkaline metals form oxides such as strontium oxide (SrO)
Answer:
HENCE (3) IS ANSWER
Explanation:
α =ΔL/(LO×Δ T) or ΔL= α(LO×Δ T)
HERE ΔL IS CHANGE IN LENGTH, Lo is original length , α is coefficient of linear expansion , Δ T is change in temperature
α= 11 x 10 ^-6/°C , Δ T = 19-20 = -1°C
hence
ΔL= 11 x 10 ^-6×10×-1
= - 11×10^-5
MINUS SIGN SHOWS SHORTER
HENCE (3) IS ANSWER
Explanation:
Speed of Bob, v = 0.967 c
At the exact instant he passes Alice, she fires a very short laser pulse in the same direction Bob is moving.
(a) We need to find the distance measured by Alice between Bob and the laser pulse. It is given by :
(b) Distance measured by Bob between himself and the laser pulse is given by :
Hence, this is the required solution.
The acceleration will be slower
Law of inertia
F=Ma 2 times slower