Answer:
dam 15 marks for that question that's ez marks there
Answer:
In the middle of a dry cell, is a rod made of carbon. Around the carbon rod is a chemical paste. At the same time, the carbon rod becomes positively charged. When this happens, electrical current flows out of the cell when a conductor is attached between the cell's positive and negative terminals.
Answer:
2 electrons will be needed by unbound oxygen in order to fill its 2nd shell.
Explanation:
The chemical reaction between magnesium and oxygen gives magnesium oxide as a product.The reaction is chemically represented as:
Magnesium is a metal of group-2 with 2 valence electrons.It has atomic number of 12.
![[Mg]=1s^22s^22p^63s^2](https://tex.z-dn.net/?f=%5BMg%5D%3D1s%5E22s%5E22p%5E63s%5E2)
In order to attain noble gas configuration it will loose two electrons.
![[Mg]^{2+}=1s^22s^22p^6](https://tex.z-dn.net/?f=%5BMg%5D%5E%7B2%2B%7D%3D1s%5E22s%5E22p%5E6)
...[1]
Oxygen is a non metal of group-16 with 6 valence electrons..It has atomic number of 8.
![[O]=1s^22s^22p^4](https://tex.z-dn.net/?f=%5BO%5D%3D1s%5E22s%5E22p%5E4)
In order to attain noble gas configuration it will gain two electrons.
![[O]^{2-}=1s^22s^22p^6](https://tex.z-dn.net/?f=%5BO%5D%5E%7B2-%7D%3D1s%5E22s%5E22p%5E6)
..[2]
2 electrons will be needed by unbound oxygen in order to fill its 2nd shell.
Answer:
3.1 m/s
Explanation:
The total distance she has to run is the addition of the three lengths:
47 + 63 + 76 = 186 meters.
She needs to cover it one minute (60 seconds). Therefore her speed must be:
186 m / 60 s = 3.1 m/s
Answer:
a) During the reaction time, the car travels 21 m
b) After applying the brake, the car travels 48 m before coming to stop
Explanation:
The equation for the position of a straight movement with variable speed is as follows:
x = x0 + v0 t + 1/2 a t²
where
x: position at time t
v0: initial speed
a: acceleration
t: time
When the speed is constant (as before applying the brake), the equation would be:
x = x0 + v t
a)Before applying the brake, the car travels at constant speed. In 0.80 s the car will travel:
x = 0m + 26 m/s * 0.80 s = <u>21 m </u>
b) After applying the brake, the car has an acceleration of -7.0 m/s². Using the equation for velocity, we can calculate how much time it takes the car to stop (v = 0):
v = v0 + a* t
0 = 26 m/s + (-7.0 m/s²) * t
-26 m/s / - 7.0 m/s² = t
t = 3.7 s
With this time, we can calculate how far the car traveled during the deacceleration.
x = x0 +v0 t + 1/2 a t²
x = 0m + 26 m/s * 3.7 s - 1/2 * 7.0m/s² * (3.7 s)² = <u>48 m</u>
