Answer:
<em>The fringe spacing on a distant diffraction screen will increase.</em>
Explanation:
Blue light has a shorter wavelength than red light, so, changing from blue to red light is basically increasing the wavelength of the light involved in the experiment.
In the double slit experiment, the fringe spacing on a diffraction screen is calculated from the equation below
ω = zλ/d
where ω is the fringe spacing
z is the distance of the slit to the screen
λ is the wavelength of the light used
d is separation or distance between the slits
From the equation, one can see that if other parameters are held constant, <em>increasing the wavelength will lead to an increase in the spacing between the fringes, and hence, changing the light from blue to red light will increase the fringe spacing.</em>
Hi Babylilith32,
Your Question:
An experiment was devised to investigate the effects on the temperature of a cup of coffee when cream is added at different time intervals. Hot and cold water were used instead of coffee and cream. First, a container of water heated to 80°C was allowed to sit for 15 minutes. Its temperature was measured at regular intervals. Next, similar temperature measurements were taken for 15 minutes on a new container of heated water, but this time some cold water was added after the 2-minute reading. Finally, the procedure was repeated except that for this last test, the cold water was added after the 12-minute reading. The resulting recorded temperatures were plotted on the graph shown here.
Answers:
1. If you have cool water then you have to add it to the hot water after a few minutes.
2. The independant variable is the cold water
3. The dependant variable is the temperature
4. The control is the hot water without the cold water.
5. The 2 min cold water drops way to much.
The vacuum layer will prevent heat losses due to conduction and convection completely as it will provide no medium for these phenomena.
The bead has a positive charge and so does the proton (+1.6*10⁻¹⁹ C), so they will repulse each other, sending the proton away from the bead, giving it a negative acceleration. For the magnitude, let's use Coulomb's Law: F = Kqq/r², where F is force, K is the electrostatic constant (9*10⁹ N*m²/C²), the q's are the charges and r is the distance between them. Plugging in values (remember that the nano- prefix corresponds to 10⁻⁹ and the centi- prefix is 10⁻²), we get F = (9*10⁹)*(30*10⁻⁹)(1.6*10⁻¹⁹)/(1.5*10⁻²)² = 1.92 *10⁻¹³ N. Ok, now that we have the force between the glass bead and the proton, we can use Newton's 2nd law: F = ma, where m is mass of the proton (1.67*10⁻²⁷ kg) and a is acceleration, to find the acceleration. Solving for a, a = F/m = (1.92 *10⁻¹³ N)/(1.67*10⁻²⁷ kg) = 1.15*10¹⁴ m/s².