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Questions in physics

[Free] An electric device delivers a current of [tex]$15.0 A$[/tex] for 30 seconds. How many electrons flow through it?

[Free] What does the wavelength of a wave measure? A. The height of the wave B. The speed of the wave C. The width of the wave D. The number of waves per second

[Free] A projectile is launched off the roof of a 200-meter-tall building close to its edge, where the initial velocity's horizontal component is [tex]$10 m / s$[/tex] and its vertical component is [tex]$15 m / s$[/tex]. If the projectile lands on the ground below, how far from the building's side (in meters) does the projectile land? Round your answer to the nearest hundredth (0.01). Hint: Find the time it spends in mid-air using the quadratic equation, then use that time to find the distance. If [tex]$A t^2+B t+ C =0$[/tex], then [tex]$t=\frac{-B+\sqrt{B^2-4 A C}}{2 A}$[/tex] It should give you two values for time; make sure to pick the right one!

[Free] An electric device delivers a current of [tex]$15.0 A$[/tex] for 30 seconds. How many electrons flow through it?

[Free] Which equation correctly represents the mechanical energy of a system? A. [tex]$ME =\frac{1}{2} m v^2-m g h$[/tex] B. [tex]$ME =\frac{1}{2} m v^2+m g h$[/tex] C. [tex]$ME =\frac{\frac{1}{2} m v^2}{m g h}$[/tex] D. [tex]$ME =m g h-\frac{1}{2} m v^2$[/tex]

[Free] An electric device delivers a current of [tex]$15.0 A$[/tex] for 30 seconds. How many electrons flow through it?

[Free] the volume of the gas when the absolute temperature is 375 K. (1) Boyle's law states that for a given mass of an ideal gas at a constant temperature, its pressure ([tex]$p N / m ^2$[/tex]) is inversely proportional to its volume ([tex]$\left(V m^3\right)$[/tex]). At a certain temperature, [tex]$3 m^3$[/tex] of a gas exerts a pressure of [tex]$10^5 N / m ^2$[/tex]. If the gas expands to [tex]$12 m^3$[/tex], calculate its pressure, giving your answer in standard form.

[Free] According to the law of conservation of energy, which statement must be true? A. There is only one form of energy. B. The total energy of a system can decrease only if energy leaves the system. C. A system cannot take in additional energy. D. Potential energy can only change to kinetic energy.

[Free] Which one of the following is a scalar quantity? (i) distance (ii) displacement (iii) velocity (iv) Gravity

[Free] Four waves are produced when a harp is strummed at four different times. | Wave 1 | Wave 2 | Wave 3 | Wave 4 | |---|---|---|---| | A thick, middle string is strummed at 70 dB. | A thick, middle string is strummed at 26 dB. | The long, thin string on one end of the harp is strummed at 20 dB. | The short, thin string on one end of the harp is strummed at 56 dB. | Which wave will produce the highest pitch? A. Wave 1 B. Wave 2 C. Wave 3 D. Wave 4