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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] 9. The number of photoelectrons emitted for light of frequency v (higher than the threshold frequency v₀) is proportional to: (a) Frequency of light (v) (b) v - v₀ (c) Threshold frequency (v₀) (d) Intensity of light

[Free] Which of these results in kinetic energy of an object? A. position B. motion C. mass D. volume

[Free] Select the correct answer. Mary pushes a crate by applying force of 18 newtons. Unable to push it alone, she gets help from her friend, Anne. Together they apply a force of 43 newtons, and the crate just starts moving. If the coefficient of static friction is 0.11, what is the value of the normal force? A. [tex]$2.0 \times 10^2$[/tex] newtons B. [tex]$2.6 \times 10^2$[/tex] newtons C. [tex]$3.9 \times 10^2$[/tex] newtons D. [tex]$4.0 \times 10^2$[/tex] newtons E. [tex]$4.3 \times 10^2$[/tex] newtons

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

[Free] 1. $\qquad$ is the study of stationary electric charges or electric charges at rest: A. magnetics B. electrodynamics C. electrostatics D electromagnetism 2. In certain experiments, an object can be charged by rubbing and contact between charged and e. electrostatics D electromagnetism uncharged objects A. false (1). true C. not given D. Uncertainty 3. ................v.proposed the single fluid model of electrostatics A. Benjamin Franklin B. Jack Ziba C. Roy Cliff D. Isaac Newton 4. Surplus of electric fluid makes the object charged charged $\qquad$ while shortage of this fluid makes it A. $+- B -+$ C. ++ D.- 5. Normal atoms are not charged as the charg: of the electrons balances the charge of their $\qquad$ A. atom B. Curve C. Core D. None of the above 6. Materials with properties intermediate between conductors and insulators are called A. intrinsic conductors $B$. extrinsic conductors $C$. semiconductors $D$. all of the above 7. $\qquad$ law provide a method to calculate any electric field with its only practical application in fields of highly symmetric distributions of fixed charges A. Gauss's Law B. Coulomb's Law C. Maxwell's Law D. Lenz's Law 8. In drawing electric field lines for any static copfiguration of charges, the lines begin on $\qquad$ charges and terminate on $\qquad$ charges $\qquad$ A. +- B. C. ++ D. $\qquad$ 9. The electric field is defined as the force per unit charge exerted on a small text positive charge placed at any point, which of this expressions describes the definition A. $\varepsilon_0=\frac{1}{4 \pi k}$ B. $E=\frac{F}{q}$ C. $F=$ $k_1 q_1 q_2$ D. $F=\frac{q_1 q_2}{4 \pi \varepsilon_0 r^2}$

[Free] What is a decibel (dBspl)? (A) A type of signal distortion (B) A mathematical constant (C) A measure of sound intensity (D) A unit of frequency

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

[Free] Convert 52 °F to degrees Celsius. 52 °F = [ ? ] °C

[Free] A projectile is launched off the roof of a 180-meter-tall building close to its edge, where the initial velocity's horizontal component is [tex]$20 m / s$[/tex] and its vertical component is [tex]$25 m / s$[/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]$t=\frac{-B \pm \sqrt{B^2-4 A C}}{2 A}$[/tex] It should give you two values for time; make sure to pick the right one!