Find the wavelength of the balmer series spectral line corresponding to n = 15.

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

truck y has a greater velocity than truck x.

when two balls of the different masses are dropped from equal height, they reach the ground at the same time .this is because they experience the same acceleration.

the acceleration is independent of mass.

thus when they are dropped they will always maintain the same velocity and travel the same distance (neglect air resistance of course) at the same time.