Answer:
371.2 mm
Explanation:
The Balmer series of spectral lines is obtained from the formula
1/λ = R(1/2² -1/n²) where λ = wavelength, R = Rydberg's constant = 1.097 × 10⁷ m⁻¹
when n = 15
1/λ = 1.097 × 10⁷ m⁻¹(1/2² -1/15²)
= 1.097 × 10⁷ m⁻¹(1/4 -1/225)
= 1.097 × 10⁷ m⁻¹(0.25 - 0.0044)
= 1.097 × 10⁷ m⁻¹ 0.245556
= 2.693 10⁶ m⁻¹
So,
λ = 1/2.693 10⁶ m⁻¹
= 0.3712 10⁻⁶ m
= 371.2 mm
Answer:
420J
Explanation:
Power is the time rate of change in energy. Power is the ratio of energy to time. The S.I unit of power is in watts.
Given that the flash lasts for 1/675 s, power output is 2.7 * 10⁵ W. Hence:
Power = Energy / time
Substituting:
2.7 * 10⁵ W = Energy / (1/675)
Energy = 2.7 * 10⁵ W * 1/675 = 400J
Therefore the energy emitted as light is 400J.
Since the conversion of electric energy to light is 95% efficient, hence the energy stored as electrical energy is:
Energy(capacitor) = 5% of 400J + 400J = 0.05*400 + 400
Energy(capacitor) = 420J
3 m/s because when he hits the water he will be traveling at the same speed
1.12 m/s is the velocity. You can get the velocity of a wave by multiplying the frequency and wavelength together. The product is the velocity.
Answer:
m = 82.1 kg
Explanation:
For this exercise we must use Hook's law that states that the force exerted by a spring is proportional to the displacement
Fe = -k x
Let's use Newton's second law to establish equilibrium, the elastic force up and the body weight down
Fe - W = 0
Fe = W = mg
k x = m g
m = k x / g
Let's reduce the distance to SI units
x = 25 cm (1 m / 100cm) = 0.250 m
m = 3220 0.250 /9.8
m = 82.1 kg
