Explanation:
Natural length of a spring is 
. The spring is streched by 
. The resultant energy of the spring is 
.
The potential energy of an ideal spring with spring constant 
and elongation 
is given by 
.
So, in the current problem, the natural length of the spring is not required to find the spring constant .
∴ The spring constant of the spring = 
It means the speed is constant with a value of 4 units.
Answer:
<u>20 Minutes</u>
<u></u>
Explanation:
Well we know Mph (Miles per hour) is distance over time : 
R (rate) = 60
d (distance) = 20
t (time) = Unknown
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
R = 
↓
60 = 
↓
t = 
↓
t = 
or 0.3333
<em>So basically it would take one third of an hour. Lets change these units to minutes.</em>
60 * 0.333333 = 20
<em>So it would take you </em><u><em>20 minutes</em></u><em> to drive 20 miles on a bus that drives 60 mph</em>
<em />
Hope that helps
<em>~Siascon~</em>
Answer:
Velocidad en m / s = 72,25 m / s
Explanation:
Dado
Distancia a recorrer por el coche de carreras = 87 Km
1 km = 1000 m
Por lo tanto, 87 km = 87000 m
Tiempo necesario para viajar 87 km / 87000 metros = 20 minutos o 20 * 60 = 1200 segundos
Velocidad en m / s = 87000/1200
Velocidad en m / s = 72,25 m / s
<span>step 1: energy required to heat coffee
E = m Cp dT
E = energy to heat coffee
m = mass coffee = 225 mL x (0.997 g / mL) = 224g
Cp = heat capacity of coffee = 4.184 J / gK
dT = change in temp of coffee = 62.0 - 25.0 C = 37.0 C
E = (224 g) x (4.184 J / gK) x (37.0 C) = 3.46x10^4 J
step2: find energy of a single photon of the radiation
E = hc / λ
E = energy of the photon
h = planck's constant = 6.626x10^-34 J s
c = speed of light = 3.00x10^8 m/s
λ = wavelength = 11.2 cm = 11.2 cm x (1m / 100 cm) = 0.112 m
E = (6.626x10^-34 J s) x (3.00x10^8 m/s) / (0.112 m) = 1.77x10^-16 J
step3: Number of photons
3.46x10^4 J x ( 1 photon / 1.77x10^-16 J) = 1.95x10^20 photons</span>
