Answer:
13. c) Net
14. a) Gravity
15. d) Watt
16. b) the speed will suddenly decrease.
Explanation:
13. The <u>net </u> force is combination of all individual forces.
14. When we sit on the chair , then <u>gravitational force</u> acts on our body due to our mass.
F = mg
here, F = force due to gravity , g = acceleration due to gravity and m= mass of the body
15.Power : It is the force acting per unit area .It is discovered by James Watt
Its unit is 
.In honor of the Scientist , its unit is Watt.
Watt =
16. When the parachute first opens , the <u>speed of the skydiver suddenly decreases</u> because of the resistance offered by the air particles.(For more details look at the figure attached)
17. Transfer of momentum from one object to other is t<u>he law of conservation of momentum</u><u> </u>(NOT ENERGY).So the answer is<u> </u><u>False</u>
<u> Law of Conservation of Momentum : </u> Total momentum of a system is conserved if no external force attack on it. Momentum can neither be created nor destroyed but transferred from one form to other.
Answer:
In acid – base chemistry, salts are ionic compounds that result from the neutralization reaction of an acid and a base. Basic salts contain the conjugate base of a weak acid, so when they dissolve in water, they react with water to yield a solution with pH greater than 7.0.
Explanation:
Hope this helped!
Answer:
77.248 L
Explanation:
From the question,
Work done on the gas mixture is given as,
W = PΔV.................. Equation 1
Where W = work done, P = pressure of the the gas, ΔV = Change in volume of the gas.
make ΔV the subject of the equation
ΔV = W/P..................... Equation 2
Given: W = 28.2 J, P = 0.37 atm = (0.37×101325) N/m² = 37490.25 N/m²
Substitute into equation 2
ΔV = 28.2/37490.25
ΔV = 0.000752 m³
ΔV = 0.752 L
But,
ΔV = V₂-V₁................. Equation 3
Where V₂ = Final volume of the helium gas, V₁ = Initial volume of the helium gas
make V₁ the subject of the equation
V₁ = V₂-ΔV................ Equation 4
Given: V₂ = 78 L.
Substitute into equation 4
V₁ = 78-0.752
V₁ = 77.248 L
Answer:
Atomic number = 16, Atomic mass = 34, Net charge= +3
Explanation:
i) Atomic number = Proton number = 16
ii) Atomic mass = Proton number + Neutron number
= 16 + 18 = 34
iii) Net charge= Proton number = Electron number (when element is in ground state or unreacted state)
But, proton number (16) is not the same as electron number (13), this means the element has lost 3 electrons
Thereore, the net charge is = 16-13
= +3
