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.
Work = (force) x (distance)
When a force of 150 N pushes through a distance of 13 meters,
it does
Work = (150 N) x (13 m) = 1,950 joules .
Answer:
Hund's rule
Explanation:
Hund's rule is defined as the rule whose first rule in the chemistry says that, for a given electronic configuration, the term which posses lowest energy has maximum multiplicity. The multiplicity is defined as the tem 2S+1, where S is the total spin angular momentum.
Therefore, the term which has lowest energy that term posses maximum number of S.
Hund's rule of maximum multiplicity: Electron present in same energy orbitals firstly they completed half orbit than start pairing.
Therefore, the energy of lowest configuration for an atom is the one having the maximum number of unpaired electron which is allowed by the Pauli principle in a particular set of degenerate orbit is called Hund's rule.
Answer:
a burning piece of converts Chemical energy into Heat(Thermal) and Light energy
Answer:
-There are no other charges nearby.
Explanation:
-There are no other charges nearby.
If there is no net charge in nearby space then the force on this charge will be ZERO
-If there are other charges nearby, they must all have the same sign as Q.
There there is nearby charge of same sign then it will have repulsion force on Q
-If there are other charges nearby, they must all have the opposite sign of Q.
if there is nearby charge of opposite sign then the force must be attraction force.
-If there are other charges nearby, the total positive charge must equal the total negative charge.
If there exist two type of charges nearby then there may exist either attraction or repulsion force on it
