Answer:
C. 720 N up
Explanation:
Newton's third law states that:
"When an object A exerts a force on an object B, then object B exerts an equal and opposite force on object A"
In this situation, we can imagine the man to be object A and the bench as object B. The force exerted by the man on the bench is:
720 N, down
So according to Newton's third law, the bench must exert an equal and opposite force on the man. Therefore, the force exerted by the bench must be
720 N, up
Answer:
<em>Reaching activation energy</em><em> is necessary because reactants require a </em><em>minimum</em><em> </em><em>amount of energy</em><em> start breaking a</em><em> chemical bond.</em>
Explanation:
Activation energy is the minimum amount of energy required by the reactants to initiate a chemical reaction. The unit of activation energy is joule or kilo joule per mole or kilo calories per mole. Activation energy depends on temperature.
The temperature dependence of activation energy is given by Arrhenious equation. Activation energy is a threshold value of energy. For any reaction to occur this is the minimum amount of energy required.
Answer: Plz mark me brainlest.
The pressure in the bottom of the glass is defined as P= (pv)g/A.
- V is the Volume.
- A is the Area.
- G is the acceleration due to gravity.
Answer:
a) 0.0875A
b) 2.06*10^-6m/s
Explanation:
given
Diameter, d = 2.6mm = 0.0026m
Charge, Q = 420C
Time, t = 80mins = 80*60s = 4800s
Concentration of electrons, n = 5*10^28
To find the current, recall that q = it
Therefore, i = Q/t
Current, i = 420/4800
i = 0.0875A
To get the drift velocity, recall that I = n*q*Vd*A
A = πd²/4
A = π*0.0026²/4
A = 5.3*10^-6m²
Then, Vd = I/nqA
Vd = 0.0875/(5*10^28 * 1.6*10^-19 * 5.3*10^-6)
Vd = 0.0875/42400
Vd = 2.06*10^-6m/s
Note, low Vd causes low current.
Therefore, the current is 0.0875A and the Vd is 2.06*10^-6m/s
Alveoli are tiny balloon shaped structures and are the smallest passageway in the respiratory system. The alveoli are only one cell thick, allowing the relatively easy passage of oxygen and carbon dioxide (CO2) between the alveoli and blood vessels called capillaries.
