Answer:
Explanation:
First of all, we need to calculate the energy of the x-ray photon emitted during the transition from K-shell to L-shell, and this energy is equal to the difference in energy between the two levels:
Converting into Joules,
Now we know that the energy of the photon is related to its wavelength by:
where
h is the Planck constant
c is the speed of light
is the wavelength
Re-arranging the equation for , we find
Answer:
It will take 666.7 seconds for him to complete 2 km run.
Explanation:
1 km → 1000 m
2 km → 2000 m
Here the distance is 2000 m and speed is 3 m/s
seconds _____in four significant figures.
Answer:
Minimum stopping distance = 164.69 ft
Explanation:
Speed of car = 35.6 mi/hr = 15.82 m/s
Stopping distance = 40.8 ft = 12.44 m
We have equation of motion
v² = u² + 2as
0²=15.82²+ 2 x a x 12.44
a = -10.06 m/s²
Now wee need to find minimum stopping distance, in ft, for the same car moving at 71.5 mi/h.
Speed of car = 71.5 mi/h = 31.78 m/s
We have
v² = u² + 2as
0² = 31.78² - 2 x 10.06 x s
s = 50.2 m = 164.69 ft
Minimum stopping distance = 164.69 ft
2.392 hector liters is equal to 239.2 liters
The free-body diagram of the forces acting on the flag is in the picture in attachment.
We have: the weight, downward, with magnitude
the force of the wind F, acting horizontally, with intensity
and the tension T of the rope. To write the conditions of equilibrium, we must decompose T on both x- and y-axis (x-axis is taken horizontally whil y-axis is taken vertically):
By dividing the second equation by the first one, we get
From which we find
which is the angle of the rope with respect to the horizontal.
By replacing this value into the first equation, we can also find the tension of the rope: