Answer:
The (s) indicates that the state of matter for NaHCO3 is solid.
Explanation:
When a chemical reaction is written, the state of matter for each components of the reactants and products are mentioned in brackets along with their names or formulas.
For example, NaHCO3 has (s) mentioned in the brackets. The s shows that the state of matter for NaHCO3. (l) represents liquid format. (g) represents that the state of matter is gas.
Answer:
(A) a heuristic
Explanation:
A heuristic:It is a reasoning strategy to find answers, make judgement about any something."
It is possible to choose between the options given, we have the following interpretation as; Interpretation: "A heuristic: finding answers is a thinking technique, evaluating something." Mechanism: In the heuristic approach the method is to find solutions or answers to a question by choosing the right and optimal compositions.
Explanation:
i) center of gravity (or mass)
ii) m = W/g = (160 N)/(9.8 m/s^2)
= 16.3 kg
Answer:
Force, 
Explanation:
Given that,
Mass of the bullet, m = 4.79 g = 0.00479 kg
Initial speed of the bullet, u = 642.3 m/s
Distance, d = 4.35 cm = 0.0435 m
To find,
The magnitude of force required to stop the bullet.
Solution,
The work energy theorem states that the work done is equal to the change in its kinetic energy. Its expression is given by :

Finally, it stops, v = 0



F = -22713.92 N

So, the magnitude of the force that stops the bullet is 
Answer:
Explanation:
No of atoms of Ra in 1 g of sample = 6.023 x 10²³ / 226
N = 2.66 x 10²¹
disintegration constant λ = .693 / half life
half life = 1620 x 365 x 60 x 60 x 24 = 5.1 x 10¹⁰ s
disintegration constant λ = .693 / 5.1 x 10¹⁰
radioactivity dn / dt = λN
= (.693 / 5.1 x 10¹⁰ ) x 2.66 x 10²¹
= .3614 x 10¹¹ per sec
= 3.614 x 10¹⁰ / s