HRS - Ask. Learn. Share Knowledge. Logo

Questions in physics

[Done] Two parallel rectangular plates measuring 80 mm by 12 cm are separated by 4 mm of mica and carry an electric charge of 0.48 MC. The voltage between the plates is [tex]$500 V$[/tex]. Calculate: (a) The electric flux density. (b) The electric field strength. (c) The capacitance of the capacitor, in picofarads, if the relative permittivity of mica is 5.

[Done] When a spring is compressed, the energy changes from kinetic to potential. Which best describes what is causing this change? A. work B. power C. gravitational energy D. chemical energy

[Done] An object has a mass of 13.5 kilograms. What force is required to accelerate it to a rate of [tex]$9.5 m / s ^2$[/tex]? A. 173.75 N B. 128.25 N C. 132.30 N D. 81.00 N

[Done] Observable matter makes up about what percentage of the universe? A. 5% B. 10% C. 50% D. 95%

[Done] Explain the following as applicable to: Lens Optical Centre Principal Focus Focal length

[Done] What is the definition of acceleration? A. The change in velocity B. The change in speed C. The change in velocity divided by the time during which the change occurs D. The change in velocity multiplied by the time of change

[Done] The formula [tex]$T=2 \pi \sqrt{\frac{L}{32}}$[/tex] relates the time, [tex]$T$[/tex], in seconds for a pendulum with the length, [tex]$L$[/tex], in feet, to make one full swing back and forth. What is the length of a pendulum that makes one full swing in 2.2 seconds? Use 3.14 for [tex]$\pi$[/tex]. A. 2 feet B. 4 feet C. 11 feet D. 19 feet

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

[Done] A circular observation window, 6 feet in diameter, is to be placed near the bottom of a pool 10 feet deep. Calculate the liquid pressure on the window. Hint: Density of water $=62.4 lb / ft ^3$. Round your answer to the nearest pound.

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