Answer:
the number of photons of yellow light does the lamp generate in 1.0 s is 7 x
Explanation:
given information:
power, P = 25 W
wavelength. λ - 580 nm = 5.80 x m
time, t = 1 s
to calculate the number of photon(N), we use the following equation
N = λPt/hc
where
λ = wavelength (m)
P = power (W)
t = time interval (s)
h = Planck's constant (6.23 x Js)
c = light's velocity (3 x )
So,
N = λPt/hc
= (5.80 x )(25)(1)/(6.23 x
)(3 x
)
= 7 x
Answer:
a. 2.668 m/s
b. 0.00494
Explanation:
The computation is shown below:
a. As we know that
As the wind does not move the skater to the east little work is performed in this direction. All the work goes in the direction of the N-S. And located in that direction the component of the Force.
F = 3.70 cos 45 = 2.62 N
We know that
KE1 = Initial kinetic energy
KE2 = kinetic energy following 100 m
The energy following 100 meters equivalent to the initial kinetic energy less the energy lost to the work performed by the wind on the skater.
So, the equation is
KE2 = KE1 - W
Now solve for v2
= 2.668 m/s
b. Now the minimum value of Ug is
As we know that
Ff = force of friction
Us = coefficient of static friction
N = Normal force = weight of skater
So,
Now solve for Us
= 0.00494
Answer:
volumme =0.36 ml
Explanation:
total heat required can be obtained by using following formula
.......(1)
where,
m - mass of water,
C - specific heat capacity of water and = 4.184 j g^{-1} °C
- total change in temperature. = 10°C
The density of water is 1 g/cc. hence, 200 mL of water is equal to 200 g
putting all value in the above equation (1)
q = 200*4.184* 10 ° = 8368 J.
Therefore total number of moles of ethanol required to supply 8368 J of heat is
The molar mass of ethanol is 46 g/mol.
The mass of ethanol required is 46* 0.006117 = 0.28138 g
The density of ethanol is 0.78 g/ml.
The volume of ethanol required is