The horizontal force : f = k*N
k- coefficient of friction
k = f /N
N = m * g = 45 kg * 9.81 m/s² = 441.45 N
k = 25 N : 441.45 N = 0.057
Answer C) 0.057
Answer:
A. Gamma decay
Explanation:
A form of nuclear decay in which the atomic number is unchanged is a gamma decay.
The atom has undergone a gamma decay.
In a gamma decay, no changes occur to the mass and atomic number of the substance.
- Gamma rays have zero atomic and mass numbers.
- When they cause decay, they cause no change to the mass and atomic numbers.
- They simply produce gamma rays during such reactions and these rays are very energetic.
here we can say that there is no external force on fisherman and dock
so here we will use momentum conservation theory
As per momentum conservation
initial momentum of fisherman + boat = final momentum of fisherman + boat
now we will have
so the speed of boat and fisherman will be 1.16 m/s
Answer: C. Metals are found on the left side of the periodic table.
Explanation:
The periodic table contains vertical columns called as groups and horizontal rows called as periods.
Period 2 contains 8 elements which are lithium, beryllium , boron , carbon, nitrogen, oxygen , fluorine and neon. Only Lithium and beryllium are metals.
Group 18 contains all the noble gases which are all non metals.
Metals are the elements which loose electrons easily and form positive ions. Non-metals are the elements which can gain electrons easily and form negative ions.
Metals are present on left side of the periodic table and as we move to right side of the periodic table , the metallic character decreases and thus non metals are found on the right side of the periodic table.
