Tuesday

July 29, 2014

July 29, 2014

Total # Posts: 4,343

**Physics**

F=qvB sin12⁰ 1.8F=qvBsinφ sinφ/sin12⁰ =1.8 sinφ =sin12⁰•1.8=0.208•1.8=0.374 φ=sin⁻¹0.374=22⁰

**PHYSICS help please!!!!!!!!!!**

Q(gained) =Q(lost) Q(lost) =Q₁+Q₂+Q₃ Q₁ = c₁m(Δt₁)=2020•1•(120-100) = 40400 J Q₂ = Lm=2256000•1= 2256000 J Q₃=c₂m(Δt₂)=4186•1•(100-85) = 62790 J Q(lost) =40400 +2256000+62790 =235919...

**PHYSICS help please!!!!!!!!!!**

Q(gained) =Q(lost) Q(gained) =Q₁+Q₂+Q₃ Q₁ = c₁m(Δt₁)=2020•1•(120-100) = 40400 J Q₂ = Lm=2256000•1= 2256000 J Q₃=c₂m(Δt₂)=4186•1•(100-85) = 62790 J Q(gained) =40400 +2256000+62790 =23...

**physics**

After the 1st rebounce the speed is v/2, after the 2nd rebounce – v/4, after the third rebounce –v/8, => m(v/8)²/2=mgh₁ v=sqrt(128gh₁) =141.7 m/s mv²/2=mgh h= v²/2g=141.7²/2•9.8=1024 m

**math**

An elementary school collected a total of 240 cans during a food drive. Grade 3 students collected 1/3 of all the cans grade 4 students collected 52 cans, and the rest of the cans were collected by grade 5 students. How many cans did grade 5 collect? A.28 B.80 C.108 D.188

**physics**

Assume g=10 m/s². The ball upward motion 0=v₀-gt, t=v₀/g=10/10=1 s. The train motion for time 1 s 0= v-at, a=v/t=5/1 = 5 m/s², the distance s= v t -at²/2 =5•1 -5•1²/2 = 2.5 m

**Physics. LAST PROBLEM!!**

A small metal ball with a mass of m = 82.5 g is attached to a string of length l = 1.72 m. It is held at an angle of θ = 58.5° with respect to the vertical. The ball is then released. When the rope is vertical, the ball collides head-on and perfectly elastically with ...

**physics**

y=gt²/2 t=sqrt(2y/g) =sqrt(2•920/9.8)=13.7 s

**Physics**

mv²/2=qU v=sqrt(2qU/m) R=mv/qB= (m/qB)• sqrt(2qU/m)= R3/R4 = sqrt{ 2Um q₄B²/q₃B²2Um)= =sqrt(q₄/q₃) sqrt(4e/3e)=1.15

**Physics**

T=t/N=11.8/10=1.18 s ω=2π/T=2π/1.18=5.32 rad/s T=mv²/R=mω²R=0.013•5.32 ²•0.93=0.34 N

**physics**

s=2.08 m m=0.592 kg R=0.0786 m a is the acceleration of the system (m1+m2) m₁a= T₁ m₂a= m₂g-T₂ Iε=M => mR²•a/2R = (T₂-T₁)R, T₂-T₁= ma/2, a= m₂g/( m₁+m₂+m/2)=... a=v²/2s v=sqrt(2as)=....

**physics**

s=2.08 m m=0.592 kg R=0.0786 m a is the acceleration of the system (m1+m2)

**physics**

m₁a= T₁ m₂a= m₂g-T₂ Iε=M => mR²•a/2R = (T₂-T₁)R, T₂-T₁= ma/2, a= m₂g/( m₁+m₂+m/2)=... a=v²/2s v=sqrt(2as)=... ω=v/R=...

**Physics**

Magnetic field of the current-carring wire at distance b from it is B=1/2πb If B=B(Earth)/3= 5•10⁻⁵/3 T, I=2πbB= 2π•0.3•5•10⁻⁵/3 = …

**Physics**

x=0.45 m, D=0.12 m, I= 2 A, B=2.1 kG=2100G= 0.21 T μ₀=4π•10⁻⁷ H/m B=μ₀nI = μ₀NI/x N=Bx/ μ₀I The length of the wire L=N•πD= Bx πD / μ₀I= =0.21•0.45•π•0.12/4π...

**Physics**

r1=r2=3 m

**Physics**

The speed is v=s/t=186/3=62 km/h <65 km/h He can arrive on time.

**Physics**

1. g =GM/R² g₁=GM/(R+h)² g₁/g=30/100= GM R²/(R+h)²GM => 0.3= R²/(R+h)² Solve for “h” (Earth’s radius is R = 6.378•10⁶ m) 2. mv²/(R+h)= GmM/(R+h)² v=sqrt { GM/(R+h)}

**physics**

Tsinα =ma Tcosα =mg tanα=a/g=3.2/9.8 = 0.33 α = 18°

**Physics**

E =kq/r² (a) E(x) = E₁-E₃=kq₁/r² - kq₃/r² = =9•10⁹{(1•10⁻⁶/0.23²)- (7•10⁻⁶/0.23²)}= -1.02•10⁶ V/m (b) An altitude of a triangle is h=0.46cos30=0.46•0.866=0.398 m E(y) ...

**physics**

1. Flowrate=A•v=21•0.89 = 18.69 m³/s 2. A₁v₁=A₂v₂ v₂=A₁v₁/A₂=21•0.89/17=1.1 m/s

**Math/Physics**

Q=55034175 J c(ice)=2060 J/kg•℃ λ=330000 J/kg c(water)=4183 J/kg•℃ Q=Q₁+Q₂+Q₃ Q=c(ice)m(12.15-0)+λm+c(water)m(t-0), Q/m=12.15•c(ice) +λ+c(water)•t. Solve for “t”

**physics**

R=ρL/A R =4ρL/πd² R₁ =4ρL/ (π4d²- πd²) =4ρL/ 3πd² R₁=R/3

**Physics**

sinα=R/L=0.3/1=0.3 α=17.45° mv²/R=Tsinα …..(1) mg=Tcosα …..(2) Divide (1) by (2) v²/Rg=tanα v=sqrt(R•g•tanα)= =sqrt(0.3•9.8•0.31)=0.27 m/s ω=v/R=0.27/0.3=0.9 rad/s f= ω/2π=0.9/2•3.14=...

**physics impulse**

1) p=mv=2•4= 8 kg•m/s 2) KE=mv²/2 3) At elastic collision p= - mv 4) Δp= p1-(-p2) =mv – (-mv)= 2mv 5) p(wall)= Δp=2mv 6) F•Δt=mv F= mv/ Δt

**physics**

We’ll use Kirchhoff’s Current Law: At any node (junction) in an electrical circuit, the sum of currents flowing into that node is equal to the sum of currents flowing out of that node. Node: I₁, I₂ and I₁₂ currents: I₁+I₂-I₁&...

**Physics**

sini/sinr=n2/n1 n2=n1(sini/sinr)=1.45(sin64.8/sin68.0)=...

**Ecology**

The eﬀect of humans on the environment is more drastic than that of other species because people have a greater ability to 1. adapt to seasonal changes. 2. learn new skills. 3. alter the environment. 4. eat diﬀerent types of food.

**Biology**

Eutrophication refers to 1. the concentration of a toxic substance in the tissues of organisms. 2. depletion of mineral resources as a result of leaching. 3. the warming of the earth’s surface. 4. the damage to the ozone layer that protects the earth from UV light. 5. nut...

**Physics**

http://en.wikipedia.org/wiki/Torque

**Physics**

F=Rmv=140•0.0026•510/60=3.1 N

**Physical Science**

convection.

**Physical Science**

convection.

**phical science**

Neutrinos are almost massless, travel close to the speed of light, and pass through matter almost undisturbed. Photons, on the other hand, have no mass, travel at the speed of light, yet are absorbed and/or reflected even by fairly sparse matter such as gasses. A photon has an...

**physics**

kx²/2 = mv²/2 v=sqrt(kx²/m)=sqrt(244•16•10⁻⁴/0.099) =...

**physics**

v₀ = 8.9 m/s m=4.1 kg R = 0.116 m μ=0.34 === F=ma F(fr)=μmg F=F(fr) ma= μmg a= μg=0.34•9.8=3.33 m/s² The torque M=Iε=(2mR²/5)•ε M=F(fr)•R= μmgR (2mR²/5)•ε= μmgR ε= 5μmgR/2mR²= ...

**physics**

kx²/2=mgh k=2mgh/ x²= 2•0.0961•9.8•0.591/(0.04754)²=...(N/m)

**Physics**

See my answer to a similar question below under related questions.

**Physics**

L₁= μ₀N²A/x₁ => x₁=μ₀N²A/L₁ L₂= μ₀N²A/x₂ => x₂= μ₀N²A/L₂ Δx=x₂-x₁=μ₀N²A{(1/L₁)–(1/L₂)}

**Physics**

Work=mgh==30•9.8•250 =... Power =mgh/t=30•9.8•250/30•60 =...

**physics**

a(centr)= mv²/R=0.036•36²/1.31 =…

**Chemistry**

0.25mol of CO are mixed with 0.90mol of H2 and heated to 950 degrees celcius in a 15L flask at equilibrium 0.190mol of H2O were present, what is the concentration of the other reactants and products at equilibrium and what is Kc

**Physics 1**

The law of conservation of linear momentum 0=mv-MV V=mv/M= 12•7.7/76.9 =1.2 m/s S=Vt=1.2•2•60 = 144.2 m

**physics**

ω=v/R ω =2πf v/R=2πf f=v/2πR= …

**Physics (Algerbra-based)**

a(centr) = a•cosα=14.3•cos30=… a(tang)=a•sinα=14.3•sin30=… a(centr)= v²/R, v=sqrt{a(centr) •R}=...

**physics**

The airplanes have the same speed -true The airplanes have the same velocity-false

**Physics**

http://www.physlink.com/education/askexperts/ae72.cfm

**physics**

C=Q/V C=εε₀A/d Situation I: The capacitor is disconnected from the battery, => Q=const (a) V=Q/C=Qd/εε₀A d₁=4d=> V₁=Q/C₁=Qd₁/εε₀A=4 Qd/εε₀A=4V (b) U=CU²/2=Q²d/2εε&...

**PHYSICS**

ΔKE=ΔPE=mgΔh=60•9.8•42 =24696 J

**Physics 11th Grade **

(a) cm₁(80-T)=cm₂(T-27) 2(80-T)=20(T-27) T=31.8 ℃ (b) λ= 330000 J/kg Q= λm=330000•0.1 =33000 J

**Physics**

Motion of the particle without deflection => F(el) = F mag) qE =qvB B=E/v=2607/6.81•10³=0.38 T For the second particle F=qE-qv₁B v₁=(F+qE)/qB= =1.8•10⁻⁹•3.72•10⁻¹²•2607}/ 3.72•10⁻¹²&#...

**Physics**

mv²/R=qvB R=mv/qB ΔR=R₂-R₁= =m₂v/qB - m₁v/qB= = v(m₂ - m₁)/qB)= =3•10⁵•(238-235)•1.67•10⁻²⁷/92•1.6•10⁻¹⁹•0.6= =1.7•10⁻⁴ m

**Physics**

ΔV=VB-VA =kq/r(B)-kq/r(A)= =kq{r(a)-r(B)}/r(A)•r(B). q = r(A)•r(B)•ΔV/k{r(a)-r(B)}= =(3.4-4.5)•45/9•10⁹•3.4•4.5 = = - 9.5•10⁻¹⁰ C

**Phyics**

ΔQ =4KCal=16747.2 J ΔQ=ΔU+W ΔU=ΔQ-W =16747.2-1000=15747.2 J

**physics**

ΔPE=A= q •Δφ Δφ= A/q=6.7•10⁻³/1.85•10⁻⁴=36 V

**Physics**

h= vₒ²•sin²α/2•g = =L•g•sin²α/2•g•sin2α= = L•sinα/4•cos α= =L•tanα/4

**Physics**

The voltage induced around the Al ring is ΔV=NΔΦ/Δt=Δ(0.5•B•A) /Δt = =0.5•A •ΔB /Δt. B =μ₀nI, ΔB /Δt= Δ(μ₀•nvI)/ Δt, ΔB /Δt= μ₀•n•ΔI/ ...

**Physics**

F=mg=100•9.8=980 N

**Physics**

C=q/U C=εε₀A/d q=CU= εε₀AU/d A) q1= εε₀A4V/2d= 2 εε₀AV/d B) q2 = εε₀2A2V/d= 4 εε₀AV/d max C) q3 = εε₀2A V/2d= εε₀AV/d D) q4 = εε₀A V/...

**Physics**

KE= m•v²/2 => v²= 2•(KE)/m a=v²/2•s =2(KE)/2•m•s = KE/m•s m•a=e•E E= m•a/e = m•KE/e•m•s = KE/e•s = =250•1.6•10⁻¹⁹/1.6•10⁻¹⁹•0.2 = 1250 V/m

**Physics**

A) 2ma=F-2T = > a=(F-2T)/2m = (12000-2•2100)/2•700 = 5.57 m/s² s=v²/2a = 40²/2•5.57 =143.6 m. B) T₁=ma +F(fr) =700•5.57 + 2100 =5999 N

**physics**

Angular magnification M= - F(objective)/F(eyepiece) F(objective)=1/1.2 = 0.833 F(eyepiece) = -1/220= - 0.0045 M= 0.833/0.0045 = 185

**Physics 11th grade 3**

1) F=ma => a=F/m = 75/17 = 4.4 m/s² s=v²/2a=3.75²/2•4.4=1.6 m 2) p= mv=0.18•3.75 =... 3) Impulse =mv=0.18•3.75 =... 4) Q=mcΔT=2•2060•20 = ...

**physics**

Rate of cooling R= ΔT₁/t₁=(80-50)/5=6 degr/min t₂= ΔT₂/R=(60-30)/6=30/6=5 min

**physics**

F(hor) =Fcos45 F(vert) =Fsin45

**physics**

F=ILB I=F/LB

**physics**

h=gt²/2 t=2h/g=2•0.63/9.8 =0.13 s. L=vt=0.3•0.13 = 0.039 m

**Physics**

γ=(i+2)/i=5/3=1.67 W=νRT₁ /(γ-1)}•{1-(V₁/V₂)^(γ-1)} = ={p₁V₁/(γ-1)}•{1-(V₁/V₂)^(γ-1)} = =(330000•1.2/0.67) •(1-0.5^0.67)= =591044.8•0.37 =2.2•10⁵ J

**Physics ~please help me~**

1a) W1=W2 = mgh 2a) P1 > P2 , mgh/25 >mgh/35 2) W=Fs=80•10 =800 J

**physics**

I=(0.73/2)²(4+3+5+2) = 1.87 kg•m² M=Iε=1.87•0.63 =1.175 kg•m

**physics**

http://answers.yahoo.com/question/index?qid=20090308072337AA3lVRt

**PHYSICS**

mgh=mv²/2 v=sqrt(2gh)=...

**PHYSICS**

v(fin)=v₀=20 m/s

**PHYSICS**

mgh₁-mgh₂=mv²/2 h₂=h₁-v²/2

**PHYSICS**

Simbol - Arial Unicode MS http://www.alanwood.net/unicode/fonts.html

**PHYSICS**

Q=ΔKE=mv²/2

**PHYSICS**

F=ma=mv²/2s v=sqrt(2Fs/m)

**PHYSICS**

W=kx²/2

**PHYSICS**

mgh=mv²/2 v=sqrt(2gh)=...

**physics**

Q=W=F(fr)s=μNs=μ•mg•s =…

**physics**

α=ΔL/L•ΔT α=3.6•10⁻⁵/3 ΔL = 3.6•10⁻⁵•17• (5-100)/3 = = -0.05814/3=0.01938 m

**physics**

α=ΔL/L•ΔT ΔL = α• L•ΔT=3.6•10⁻⁵•17• (5-100) = = -0.05814 m

**physics**

The time that the bullet spends in the building t=x/v(0x) =7/340 =0.02 s. The vertical displacement of the bullet in the building y= 0.56 m. The vertical component of the velocity of the bullet as it passes through the window is v(y) = (y- gt²/2)/t = y/t - gt/2= =0.5/0.02...

**Physics**

h= vₒ²•sin²α/2g, Solve for vₒ

**Physics**

T=F/cosφ =60/0.707 = =60/0.707 = 84.87 N

**Physics**

cos φ=15/40= 0.375 φ=68⁰ F=Tsin φ = 1000•sin68 =927 N

**Physics**

v₁= {+2m₂v₂₀ +(m₁-m₂)v₁₀}/(m₁+m₂) v₂={ 2m₁v₁₀ + (m₂-m₁)v₂₀}/(m₁+m₂)

**Physics**

L=v(x)•t => t=L/v(x) h=gt²/2 = gL²/2v(x)² v(x)= sqrt (gL²/2h)

**physics**

k=mg/x=2.5•9.8/0.0305 =803.3 N/m the natural frequency is ω =sqrt(k/m) = sqrt(803.3/2.5)=17.9 rad/s

**physics**

http://answers.yahoo.com/question/index?qid=20120417015851AAp5Qdo

**physics**

(a) W(grav) = 0 since there is no change in height between the initial point and point A. (b) W(grav) – mgh –mg(h/2) = mgh/2 (c) W(grav) mgh -0 = mgh (d) mgh/2 (e) mgh

**Physics**

I=ℇ/(R+r) R= (ℇ-Ir)/I= (7.9-0.88•1.37)/0.88 = … P=I²r = …

**Physics**

x=Asinωt v=dx/dt =Aω cosωt= Aω•sqrt(1-sin²ωt) = =ω•sqrt(A² - A² sin²ωt)= ω•sqrt(A² -x²) A=0.076 m x= 0.045 m ω =17.8 rad/s v= ω•sqrt(A² -x²)= …

**physics**

ΔKE=-ΔPE KE2-KE1= -(PE2-PE1) ΔKE= KE2-KE1= m(v/2)²/2-mv²/2= = mv²/8-mv²/2= - 3mv²/8, ΔPE= PE2-PE1= k•q1q2/r-0=ke²/r - 3mv²/8 = - ke²/r, r=8ke²/3mv²= ... k =9•10⁹ N•m²/C² e =1.6...

**Physics please help!!**

Kepler’s Third Law. The square of the period is proportional to the cube of the distance from the star: T²∼R³ If the distance is increased by 25, then T² is increased by 25³, which means T is increased by the sqrt(25³)=125.

**Physics please help!!**

http://answers.yahoo.com/question/index?qid=20091117133730AAqpbug

**Physics**

See the answer to a similar question below under related questions

**Physics**

Elongation of the spring is x=2.69 –(2.22+0.28) = 0.19 m mg= kx k=mg/x- 145/0.19=763.16 N/m

**Physics**

5T=68 => T=68/5=13.6 s λ=34.1 m v= λ/T f=1/T

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