Answer:
(a) 43.2 kC
(b) 0.012V kWh
(c) 0.108V cents
Explanation:
<u>Given:</u>
- i = current flow = 3 A
- t = time interval for which the current flow =
- V = terminal voltage of the battery
- R = rate of energy = 9 cents/kWh
<u>Assume:</u>
- Q = charge transported as a result of charging
- E = energy expended
- C = cost of charging
Part (a):
We know that the charge flow rate is the electric current flow through a wire.
Hence, 43.2 kC of charge is transported as a result of charging.
Part (b):
We know the electrical energy dissipated due to current flow across a voltage drop for a time interval is given by:
Hence, 0.012V kWh is expended in charging the battery.
Part (c):
We know that the energy cost is equal to the product of energy expended and the rate of energy.
Hence, 0.108V cents is the charging cost of the battery.
#3). Your drawing in the lower right corner is correct. You're headed down the right road, but ran out of gas and just stopped.
Radius of the circle = 1.5 km
Circumference of the whole circle = (2·π·radius) = 9.42 km
Distance = 3/4 of the way around it = 7.07 km .
Displacement = the straight line from the West point to the North point. The straight-line length is 2.12 km; the straight-line direction from start to finish is Northeast (45°). I'll let you figure out why these numbers.
#4). What if you walk 1 mile East and then 1 mile West ? You got a good workout, and you're back home where you started ! Your distance is 2 miles, and your displacement is zero.
The whale had a good workout too. She swam (6.9 + 1.8 + 3.7) = 12.4 km. She's sweating and tired. Her total distance during that workout is 12.4 km.
Her displacement is the line from start-point to end-point. How she got there doesn't matter, so swimming 1 km East and then swimming 1 km West cancel out, and have no effect on the displacement.
(6.9E + 1.8W + 3.7E) = (10.6 E) + (1.8 W) . . . That adds up to 8.8 East ! That's where she ends up. That's her displacement ... 8.8 km East of where she started. Since we're only talking about displacement, we don't care HOW she got there. She might have been swimming big 20-km circles all day. We don't know. All we know is that she ended up 8.8 km East of where she started.
The recoil velocity of cannon is (4) 5.0 m/s
Explanation:
We can find the recoil velocity from the law of conservation of momentum.
The recoil velocity is velocity of body 2 after release of body 1, i.e. velocity of cannon after release of clown.
Let v2 be cannon's velocity, v1 be clown's velocity given = 15 m/sec
m1 be clown's mass = 100kg and m2 be cannon's mass given = 500kg.
So recoil velocity of cannon v2 is given by,
v2 = -(m1÷m2)v1
v2 = -(100÷500)15
v2 = -5 m/s
where the minus sign refers to the direction of cannon's recoil velocity being opposite to that of clown.
Hence, option (4)5.0 m/s is the correct answer.
R 1,2 = 27.5 + 33.0 = 60.5 Ohms
1/ R 1,2,3 = 1/ 60.5 + 1 / 22 = 82.5 / 1331
R 1, 2, 3 = 1331 / 82.5 = 16.13 Ohms
I = U / R
I = 9 V / 16.13 Ohms = 0.557 A ≈ 0.56 A
Answer: C ) 0.56 Amps
