Answer:
Option C = 30 j
Explanation:
Given data:
mass of snowboard = 5 Kg
Initial speed = 2 m/s
final speed = 4 m/s
work done = ΔE= ?
ΔE= change in kinetic energy
Solution:
Formula:
K.E (initial) = 1/2 × mv²
K.E (initial) = 1/2 × 5 Kg . (2m/s)²
K.E (initial) = 1/2 × 20 Kg.m²/s²
K.E (initial) = 10 Kg.m²/s² or 10 J
Kg.m²/s² = J
K.E (finial) = 1/2 × mv²
K.E (finial) = 1/2 × 5 Kg . (4m/s)²
K.E (finial) = 1/2 × 5 Kg . 16 m²/s²
K.E (finial) = 1/2 × 80 Kg.m²/s²
K.E (finial) = 40 Kg.m²/s² or 40 J
work done = ΔE = K.E (finial) - K.E (initial)
work done = ΔE = 40 J - 10 J
work done = ΔE = 30 J
Answer:
Explanation: because more is always better
Answer:
C) LiOH + HCl → LiCl + H₂O
General Formulas and Concepts:
<u>Chemistry - Reactions</u>
- Synthesis Reactions: A + B → AB
- Decomposition Reactions: AB → A + B
- Single-Replacement Reactions: A + BC → AB + C
- Double-Replacement Reactions: AB + CD → AD + BC
Explanation:
<u>Step 1: Define</u>
RxN A: 2Na + 2H₂O → 2NaOH + H₂
RxN B: CaCO₃ → CaO + CO₂
RxN C: LiOH + HCl → LiCl + H₂O
RxN D: CH₄ + 2O₂ → CO₂ + 2H₂O
<u>Step 2: Identify</u>
RxN A: Single Replacement Reaction
RxN B: Decomposition Reaction
RxN C: Double Replacement Reaction
RxN D: Combustion Reaction
You will need Periodic Table for this problem.
As we know, the number of protons specifies Atomic number. So, the atomic number for this element is 19.
Now, element having 19 protons must have 19 electrons, So, writing electronic configuration for 19 electrons,
1s², 2s², 2p⁶, 3s², 3p⁶, 4s¹
So, valence shell is 4, means element is present in 4rt period. And number of electrons in 4rth shell are 1. Means element belong to group 1.
Take periodic table go to period 4 and group 1. Its Potassium (K).
