Answer:
What is the membrane's conductance = 2.47miuS
Explanation:
The detailed step and appropriate formula is as shown in the attached file.
when sled just start to move the force on the sled will be equal to the static friction
So here we need to find the value of static friction
We know that
m = 30 kg
now we know that normal force on the block is counterbalanced by weight of the block
now in order to find the friction force we can use
so it requires 59 N of force to move the sled
Answer:
The object is 1.2755 meters above the ground
Explanation:
Recall the formula for gravitational potential energy for an object of mass "m" at a height "h" above the ground:
In this case, since we are given the mass of the object and the object's potential energy, we can estimate the only unknown (height "h") from the formula shown above. Also since all units are given in the SI system, the result for the object's height will result in meters:
Answer:
a) 33.6 min
b) 13.9 min
c) Intuitively, it takes longer to complete the trip when there is current because, the swimmer spends much more time swimming at the net low speed (0.7 m/s) than the time he spends swimming at higher net speed (1.7 m/s).
Explanation:
The problem deals with relative velocities.
- Call Vr the speed of the river, which is equal to 0.500 m/s
- Call Vs the speed of the student in still water, which is equal to 1.20 m/s
- You know that when the student swims upstream, Vr and Vs are opposed and the net speed will be Vs - Vr
- And when the student swims downstream, Vr adds to Vs and the net speed will be Vs + Vr.
Now, you can state the equations for each section:
- distance = speed × time
- upstream: distance = (Vs - Vr) × t₁ = 1,000 m
- downstream: distance = (Vs + Vr) × t₂ = 1,000 m
Part a). To state the time, you substitute the known values of Vr and Vs and clear for the time in each equation:
- (Vs - Vr) × t₁ = 1,000 m
- (1.20 m/s - 0.500 m/s) t₁ = 1,000 m⇒ t₁ = 1,000 m / 0.70 m/s ≈ 1429 s
- (1.20 m/s + 0.500 m/s) t₂ = 1,000 m ⇒ t₂ = 1,000 m / 1.7 m/s ≈ 588 s
- total time = t₁ + t₂ = 1429s + 588s = 2,017s
- Convert to minutes: 2,0147 s ₓ 1 min / 60s ≈ 33.6 min
Part b) In this part you assume that the complete trip is made at the velocity Vs = 1.20 m/s
- time = distance / speed = 1,000 m / 1.20 m/s ≈ 833 s ≈ 13.9 min
Part c) Intuitively, it takes longer to complete the trip when there is current because the swimmer spends more time swimming at the net speed of 0.7 m/s than the time than he spends swimming at the net speed of 1.7 m/s.
You can deal with this question using the collision theory, which states that the chemical reactions occur when particles collide with enough energy to reach the Activation Energy.
The velocity of the particles is related with the temperature. At higher temperatures, higher velocities and higher frequency of collisions.
Also, at higher concentration (more particles is a same volume) the number of collisions will increase.
Then, hIgher concentration and higher temperature will increase the frequency of the molecular collisions..
Then, the answer is the proposal #1: "<span>increasing the frequency of molecular collisions"</span>
