Answer:
392
Explanation:
According to the law of conservation of energy, energy cannot vanish,so the lost potential energy must be converted into another form of energy (in this case, Kinetic Energy).
(mass*g*height)-(mass*g*halfway height)=(2*9.8*40)-(2*9.8*20)
784-392=392
This makes sense because since the rock has fallen halfway, half of its potential energy has become kinetic energy. Once the rock reaches a height of 0 Meter, all of its potential energy will be kinetic energy.
20 protons
20 electrons ( as much elctrons as protons because there has to be same positive and negative to have a neutral atom)
And the number of neutrons depends of the mass number but in that case, I think that it's a Calcium atom (Ca) and so there are 20 netrons.
Answer:
0.0008 mole of HCl
Explanation:
From the balanced equation between HCl and NaOH:

1 mole of acid requires 1 mole of base for neutralization.
mole = molarity x volume
mole of NaOH = 0.02 x 0.04 = 0.0008 mole
mole HCl = 0.16 x 0.01 = 0.0016 mole
Since 1 mole of NaOH requires 1 mole of HCl for neutralization, it means that 0.0008 mole of NaOH will require 0.0008 mole of HCl. The remaining mole of HCl must have been neutralized by the antiacid:
0.0016 - 0.0008 = 0.0008 mole.
Therefore, 0.0008 mole of HCl must have been neutralized by the antiacid.
Answer:
13.1 L
Explanation:
Using the combined gas law:
P1V1/T1 = P2V2/T2
Where;
P1 = initial pressure (atm)
P2 = final pressure (atm)
V1 = initial volume (L)
V2 = final volume (L)
T1 = initial temperature (K)
T2 = final temperature (K)
Based on the information provided in this question;
P1 = 1.95 atm
P2 = 0.65 atm
V1 = 5.0 L
V2 = ?
T1 = 20 °C = 20 + 273 = 293K
T2 = -15 °C = -15 + 273 = 258K
Using P1V1/T1 = P2V2/T2
1.95 × 5/293 = 0.65 × V2/258
9.75/293 = 0.65V2/258
0.0333 = 0.00252V2
V2 = 0.0333 ÷ 0.00252
V2 = 13.1 L
Answer:
A.0.51L
B 1.67L
Explanation:
using the formula ;C1V1 =C2V2
15.8×V1=2×4
15.8V1=8
V1=8/15.8
V1=0.51L
apply the same method for B