Answer:
See the answer below
Explanation:
1. Speed is calculated as the ratio of distance and time. Hence, Jame's speed can be calculated as:
400/5 km/hr = 80 km/hr
The unit for the speed would be km/hr. This can also be converted to m/s:
80 km = 80,000 m
1 hr = 3,600 s
80 km/hr = 80,000/3600 m/s = 22.22 m/s
2. Since James drove 400 km in 5 hours, the distance he drove is 400 km.
3. The time it took for James to get there is 5 hours.
A) 1.55
The speed of light in a medium is given by:
where
is the speed of light in a vacuum
n is the refractive index of the material
In this problem, the speed of light in quartz is
So we can re-arrange the previous formula to find n, the index of refraction of quartz:
B) 550.3 nm
The relationship between the wavelength of the light in air and in quartz is
where
is the wavelenght in quartz
is the wavelength in air
n is the refractive index
For the light in this problem, we have
Therefore, we can re-arrange the equation to find , the wavelength in air:
Answer:
The work could be either positive or negative, depending on the direction the object moves
Explanation:
Answer:
The bread will take 216.40 minutes to cool to 185°F
Explanation: Newton law of cooling
states that the rate of cooling of an object is inversely proportional to the difference of temperatures between the object and its surroundings i.e. dTdt=−kT, where t is the time taken and T is the difference of the temperatures between the object and its surroundings.
This gives us T as a function of t and is given by T(t)=ce−kt.
T(0)= Ce^-kt
C=35₩F- 185F= 165F
T(20) = 165×e^-20k=(350-70)
T(20)= e^-20k =280/165
-20k= ln(280/165)
-20k= ln(1.697)
-20k= 0.5289
K= 0.5289/20
K= 0.0264
If it cools at 185F in t minutes
165e^-0.0264×t=0.5
e^-0.0264t= 0.5/165
-0.0264t= on 3.03×10^-3
-0.0264t= -5.7129
t= 5.7129/0.0264
t=216.40minutes
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