Answer:
30 hours
Explanation:
Average speed = distance/time
Let the time taken for each plane to pass each other be t
Average speed of plane that left from New York = 650 mph
Distance covered = 650t miles
Average speed of plane that left from Mexico = 550 mph
Distance covered = 550t miles
Distance apart = 3000 miles
650t - 550t = 3000
100t = 3000
t = 3000/100 = 30 hours
Answer:
A. Part a is the attachment
B. total work = 10.4kj
Explanation:

T1 = constant temperature
nRT1 = PaVa = PbVb
We write equation as

5ma = Pa, 5L = Va, Vb = 10L(temperature is doubled)

W1 = 25 ln2
W1 = 25 x 0.693
= 17.327kj
The isochoric expansion has no change in volume. So,
W2 = 0
Isothermal compression

T3 = constant temperature
nRT3 = PcVc = PdVd

Pc = 1mpa Vc = 10L Vd = 5L

= 10x-0.693
= -6.93kj
Isochoric compression has no change in volume. Workdone w4 = 0
Total workdone = w1 + w2 + w3 + w4
= 17.33 + 0 + (-6.93) + 0
= 10.4kj
Report this clown who put the first answer he’s trying to get your ip
Answer:
4. It is the force of the road on the tires (an external force) that stops the car.
Explanation:
If there is no friction between the road and the tires, the car won't stop.
You can see this, for example, when there is ice on the road. You can still apply the brakes (internal force), but since there is no friction (external force) the car won't stop.
The force of the brakes on the wheels is not what makes the car stop, it is the friction of the road against still tires that makes it stop.
Answer:
Ф = 2.179 eV
Explanation:
This exercise has electrons ejected from a metal, which is why it is an exercise on the photoelectric effect, which is explained assuming the existence of energy quanta called photons that behave like particles.
E = K + Ф
the energy of the photons is given by the Planck relation
E = h f
we substitute
h f = K + Ф
Ф= hf - K
the speed of light is related to wavelength and frequency
c = λ f
f = c /λ
Φ =
let's reduce the energy to the SI system
K = 0.890 eV (1.6 10⁻¹⁹ J / 1eV) = 1.424 10⁻¹⁹ J
calculate
Ф = 6.63 10⁻³⁴ 3 10⁸/405 10⁻⁹ -1.424 10⁻¹⁹
Ф = 4.911 10⁻¹⁹ - 1.424 10⁻¹⁹
Ф = 3.4571 10⁻¹⁹ J
we reduce to eV
Ф = 3.4871 10⁻¹⁹ J (1 eV / 1.6 10⁻¹⁹ J)
Ф = 2.179 eV