D = 40.5 g / 15.0 mL<span>d = 2.70 g/mL</span>
Answer:
Explanation:
The change in electrical potential energy of a charged particle moving through a potential difference is given by
where
q is the magnitude of the charge of the particle
is the potential difference
In this problem:
- the charge of the particle is 3.00 elementary charges, so
- the potential difference is
So, the change in electrical potential energy is
Answer: 0.85 meters (with and without sigfigs)
Explanation: To find the wavelength, you just have to switch around the equation for wave speed: v (wave speed) = λ (wavelength)*f (frequency) so λ (wavelength) = v (wave speed)/f (frequency). You don't have the wave speed but you can calculate it. Since wave speed is measured in meters/second or m/s, you just have to divide the amount of meters you were given by the amount of seconds. You will get 340 m/s. Next, you have to plug the values into the equation: λ (wavelength) = 340 m/s (wave speed)/400 Hz (frequency). The answer is 0.85 meters (seconds cancel) and has the correct number of significant figures.
