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September 5, 2015

Posts by Elena


Total # Posts: 4,370

Physics
L=L₀•sqrt{1-(v/c)²}=0.866L₀ The length of the rod will decrease.
October 23, 2012

Physics
Jenifer is right 1/F = 1/0.2 – 1/0.125 – 1/0.4 +1/0.1429 = =5-8-2.5+7 = +1.5 F= + 0.667 m
October 23, 2012

Physics
Lens 1- F'= +200mm=+0.2 m Lens 2- F'= -125mm = - 0.125 m Lens 3- F'= -400mm =- 0.4 m Lens 4- F'= +142.9mm= +0.1429 m 1/F = 1/0.2 – 1/0.125 – 1/0.4 +1/0.1429 = =5-8-2.5+7 = -3.5 F= - 0.286 m
October 23, 2012

Physics
C=Q/(T2-T1) c=Q/m(T2-T1)
October 23, 2012

physics to be conceptualize
In an isolated system where only conservative forces cause energy changes, the kinetic energy and potential energy of the system can change, but the mechanical energy of the system cannot change. The work done by a conservative force on a particle moving between two points ...
October 23, 2012

Physics helppp
An isolated system is one in which objects inside the system are not influenced by any forces from outside the system.
October 23, 2012

Physics Please help !!
ΔU = U(x) - U(0) = ∫(6x - 12)dx Therefore, with U(0) = 23 J, we obtain by integrating U = 23 + 12x - 3x ² F = 0 when 6x - 12 = 0 Thus x = 2 m Substituting into U = 23 + 12x² - 3x , U = 35 J Using the quadratic equation find the negative and positive values...
October 23, 2012

physics
55 µm =55•10⁻⁶ m=0.000055 m=5.5 •10⁻⁷ m
October 22, 2012

physics
10.1 nm =0.0000000101=1.01•10⁻⁸ m= =1.01•10⁻ ⁵mm=1.01•10⁻ ²µm
October 22, 2012

physics
2. x = v t
October 22, 2012

Physics
F=qvBsinα sinα=1 => F=qvB F(p)=e2vB F(e) =evB F(p)/F(e) =2 ...2:1
October 22, 2012

Physics
m1+m2+m3 = 92.5 kg. m1= 0.31 kg m2+m3 =92.19 kg v=0.55 m/s v1= - 17 m/s v2=? (m1+m2+m3) •v= - m1•v1+(m2+m3) •v2 v2= {(m1+m2+m3) •v +m1•v1}/(m2+m3)=…
October 22, 2012

Physics
3/sqrt2 = 2.1 A
October 22, 2012

physics
r(x)= 13.8•cos15.5◦ r(x)= 13.8•sin15.5◦
October 22, 2012

Physics
Change of the horizontal component of the stone’s linear momentum is Δp(x) = m•v(0x) – (-mv(1x)} = m{v(ox)+v(1x)} = m{v(0) •cos15 +v1•cos12} For the boat Δp=p2-p1 = M•u – 0 = M•u. Thje law of conservation of linear momentum &#...
October 22, 2012

physics
h=v²/2g
October 22, 2012

PHYSICS
m•g=k•x₁ k= m•g/x₁=0.116•9.8/0.035= 32.5 N/m When the spring rises 5.7 cm =0.057 m and the spring is compressed to x₂=0.022 m F= k•x₂ =ma a =k•x₂ /m=32.5•0.022/0.116 =6.16 m/s²
October 22, 2012

Physics
The rope it attached to the man’s hands, and the chair he is in. So, there are two tensions pulling upward on the “child-chair” system. m=(287+223)/g=510/g, T=265 N 2T=mg +ma ma= (2T-mg)/m = =g (2•265- 510)/510= =9.8(530-510)/510= =0.38 m/s² N=...
October 22, 2012

physics help i still dont get it
sinα =2,5/sqrt{2.5²+(43/2)²} =0.116 m•g=2•T•sinα T=m•g/2•sinα =52/2•0.116 =225 N
October 22, 2012

physics help i still dont get it
sinα =2,5/sqrt{2.5²+(43/2)²} m•g=2•T•sinα T=m•g/2•sinα
October 22, 2012

physics
F(net)=sqrt(F1²+F2²) a=F(net)/m
October 22, 2012

physics
m=1500/9.8 kg F=ma =0.8•1500/9.8= …(N)
October 22, 2012

Physics
(a) v₂= 2m₁v₁₀/(m₁+m₂) =2•5.9•27.6/(5.9+17.7)=13.8 cm/s (b) KE1(fin) –KE1(init) =m₁ •v₁₀²/2 –m₁•v₁²/2=0.5•m₁ (v₁₀² –v₁²)= =0.5...
October 22, 2012

Physics
Number of turns in the primary coil is more than the number of turns in the secondary coil.
October 22, 2012

physics
m•g=k•x₁ k= m•g/x₁=0.116•9.8/0.035= 32.5 N/m When the spring rises 5.7 cm =0.057 m and the spring is compressed to x₂=0.022 m F= k•x₂ =ma a =k•x₂ /m=32.5•0.022/0.116 =6.16 m/s²
October 22, 2012

Physics
I1=U/R1=6.3 =2 A
October 22, 2012

physics need help bad
Find the answer in the Related Questions
October 22, 2012

Physics
The rope it attached to the man’s hands, and the chair he is in. So, there are two tensions pulling upward on the “child-chair” system. m=(287+223)/g=510/g, T=265 N 2Tmg ma ma= ( 2T-mg)/m = =g (2•265- 510)/510= =9.8(...
October 22, 2012

Physics
1/R(eq)=3/R R(eq)=R/3
October 22, 2012

Physics
m1•v= (m1+m2) •u u = m1•v/ (m1+m2)
October 22, 2012

physics
(a) KE= KE(transl) +KE(rot) = m•v²/2+Iω²/2= = m•v²/2+ (2mR²)• v²/5•2•R²= = m•v²/2+ mv²/5 =0.7 mv² (b) KE=PE 0.7•m•v²=mgh h= 0.7•v²/g =…
October 22, 2012

Physics
(a) L1 = M•v•R = Earth’s mass is M = 5.97•10^24 kg, R= 1.5•10^11 m (Earth-Sun) v=ω•R=2•π•n•R n=1 rev/year =1/365•24•3600 rev/s L1 = M•v•R = M•2πn•R²= …(kg•m²/s) (b) ...
October 22, 2012

Physics
ma= mg - N N=mg -ma
October 22, 2012

Physics
ma=-mg+N N=ma+mg
October 22, 2012

physics
v=v₀-at a= (v₀-v)/t s=v₀t -at²/2
October 22, 2012

physics
m•g=k•x₁ k= m•g/x₁=0.116•9.8/0.035= 32.5 N/m When the spring rises 5.7 cm =0.057 m and the spring is compressed to x₂=0.022 m F= k•x₂ =ma a =k•x₂ /m=32.5•0.022/0.116 =6.16 m/s²
October 22, 2012

Physics
ΔE=0.17 J, h=L(1-cosα) PE=KE+ΔE mgh=mv²/2 + ΔE mv² =2{mgL(1-cosα)- ΔE} T= mv²/L + mg = 2{mgL(1-cosα)- ΔE}/L +mg
October 22, 2012

physics
m•g=k•x₁ k= m•g/x₁=0.116•9.8/0.035= 32.5 N/m When the spring rises 5.7 cm =0.057 m and the spring is compressed to x₂=0.022 m F= k•x₂ =ma a =k•x₂ /m=32.5•0.022/0.116 =6.16 m/s²
October 22, 2012

Physics
(a)ma=F-F(fr) F(fr)= F-ma (b) F(fr) =μmg μ=F(fr)/mg
October 21, 2012

Physics
m=F/a
October 21, 2012

Physics
F(y) =Fsinα
October 21, 2012

Physics
g(Moon) =g1=1.63N/kg. m=W1/g1=2000/1.63=1227 kg W(Earth)=W2=mg=1227•9.8=12025 N
October 21, 2012

physics
v=v₀+at v₀=0 v=at a=v/t s=at²/2
October 21, 2012

physics
ma=F(fr) =μmg a= μ•g v=v₀-at
October 21, 2012

physics
1. N1=(m(per) +m(cr))g 2. N2=m(per)g
October 21, 2012

Physics
zero V/m
October 21, 2012

Physics
Ñ=q/V= 3.3x10^-6 F
October 21, 2012

Physics
(a) Torque1= W•L•sinα = 12000•2.5•sin32°=… (b) Torque2=T•L•cosα=54200•2.5•cos32°=…
October 21, 2012

physics
T1= 101◦F =311.48K T2= 70°F=294.26 K Since the emissivity is 1, the object is the black body => P=R•A= σ•T⁴•A ΔP= σ•T1⁴•A - σ•T2⁴•A = σ•A•( T1⁴ - T2⁴)= =5.67•...
October 21, 2012

Physics
n=33rpm=33/60 =0.55rev/sec ω =2πn=2π•0.55=3.45 rad/s The rod is rotating clockwise about ITS CENTER OF MASS. The center of mass is at r=4.63/2 =2.315 m from each end of the rod.Then M=Iε =(m1•r²+m2•r²)•ω/t = r²(m1+m2...
October 20, 2012

physics
1. N1=(m(per) +m(cr))g 2. N2=m(per)g
October 20, 2012

physics
c. takes a short time to cool off.
October 20, 2012

Physics
Work=P •m•t= P•m•s/v= =6.5•75•145000/13.5=5.23•10⁶J = = 1.25•10³ nutr.Cal. Now it's OK
October 20, 2012

Physics
Work=P •m•t= P•m•s/v =6.5•75•145000/13.5=5.23•10⁶J =1.25 nutr.Cal.
October 20, 2012

Physics
Work= •m•t= P•m•s/v =6.5•75•145000/13.5=5.23•10⁶J =1.25 nutr.Cal.
October 20, 2012

Physics
Power is the rate of energy (here, kinetic energy) => P=W/t= mv²/2t = 114•18.2²/2•2.7 = 6993 W = =9.37 hp 1 hp = 745.66272 W
October 20, 2012

Physics
m•v²/2=mgh=m•g•s•sinα v=sqrt(2• g•s•sinα)
October 20, 2012

Physics
m•v1²/R1=T1 m•v2²/R2=T2=4•T1 v2²=4•v1²•R2/R1 W=KE2-KE1 = m•v1²/2 - m•v2²/2 = = m•v1²/2- m• 4•v1²•R2/2•R1 = = m•v1² { 1- (2•R2/R1)}/2= = 0.82•21²{1-(2&#...
October 20, 2012

physics
KE=PE KE= KE(transl) +KE(rot) = =m•v²/2+Iω²/2= = m•v²/2+ (2mR²)• v²/5•2•R²= = m•v²/2+ mv²/5 =0.7 mv² 0.7•m•v²=mgh v=sqrt(g•h/0.7)
October 19, 2012

Physics
Guitar pickups are tiny coils with magnets inside them. The magnets magnetize the steel strings. When the strings vibrate, voltage is induced in the coils and boosted by an amplifier, and sound is produced by a speaker.
October 19, 2012

Physics
2Tsinα=mg T=mg/2sinα
October 19, 2012

Physics
t=s/{v(plane)-v(wind} !!! km/h -> m/s
October 19, 2012

Physics
T=mgsinα
October 19, 2012

Physics
F=2•F(fr)+mg =2•μ•N +mg N=(F+mg)/2• μ
October 19, 2012

Physics
Figure???
October 19, 2012

Physics
h = v²/2g
October 19, 2012

physics
γ= 2.675•10⁸ T⁻¹•s⁻¹ γ/2π =42.58 MHz/T f= γ•B = 2.675•10⁸•3 = 8.0250•10⁸s⁻¹ B1=3 + 3•10 ⁻⁵•10=3+3•10⁻⁴ T=3.0003 T f1= γ•B1 = 2....
October 19, 2012

physics
v=5.2/tan30 = 9m/s
October 19, 2012

Physics
h=v²/2g=5.6²/2•9.8 =1.6m. Upward motion W1=-mgh= - 0.135•9.8•1.6= - 2.12 J Downward motion W2= mg(H+h) = 0.135•9.8•(1.94+1.6) =4.68 J W= W1+W2 = -2.12 +4.68 = 2.56 J.
October 19, 2012

physics
F(fr)=mv²/R
October 19, 2012

physics is annoying
ΣFx= -F(A) •cos47 +F(C)cosφ=0 ΣFy= F(A) •sin47 +F(C) sinφ –F(B) =0 -227•0.68 +175•cosφ=0 227•0.73 +175•sinφ –F(B) = 0 154.36 =175•cosφ cosφ=154.36/175 = 0.88 φ= 28.36° sin28.36°=0...
October 19, 2012

physics to be solved ..easy !!
Misprint Vy•t - a•t²/2 = 2.11. The solution is correct. Check my calculations
October 19, 2012

physics to be solved ..easy !!
Vx•t = 15.1 V•cos(33.8) •t = 15.1 t=15.1/(V•cos33.8) (1) Vy•t+ a•t²/2 = 2.11 V•sin(33.8)•t - 0.5•(9.8)•t²= -2.11 (2) Plugging (1) into(2) V•sin(33.2)( 15.1/(V•cos33.8) - 4.9•{15.1/(V•cos33.8) }2...
October 19, 2012

physics help needed very urgent !!!
m1 = 10.5 kg, m3 = 14.7 kg, m4 = 22.05 kg, T2 = 120 N, and T4 = 236 N. m2=? (m1+m2+m3+m4)a=T4 (m3+m4)a=T4-T2 (10.5+m2+14.7+22.05)a =236 (14.7+22.05)a=236-120 a=116/36.75 =3.16 m/s² (10.5+m2+14.7+22.05)a =236 m2={236-(10.5+14.7+22.05)3.16}/3.16 = 27.43 kg
October 19, 2012

Physics
ma=μmg a=μg v=v₀-at,
October 19, 2012

Physics URGENT!!!
Please see the Related Questions below
October 19, 2012

Physics
E = v / d
October 19, 2012

Physics
N=q/e =6•10⁻⁶/1.6•10⁻¹⁹=3.75•10¹³=4•10¹³
October 19, 2012

physics
s=s1+s2+s3 =20•2+40•2+60•6 =480 m t=t1+t2+t3 =2+2+6 =10s v(ave) =s/t =480/10=48 m/s ---D
October 19, 2012

physics
F1+F2=F(fr)=μ•m•g μ=(F1+F2)/m•g
October 19, 2012

Physics
Value of the force is decreased by four. F=k•q1•q2/r² If r2=2•r1, F2=F1/4
October 19, 2012

Physics
F=qvBsinα If sinα=0 F=0
October 19, 2012

colledge physics
Question???????
October 19, 2012

Physics
I=Imax/sqrt2=2.1 A
October 19, 2012

Physics
The light waves are out of phase with each other.
October 19, 2012

Physics
ΔPE=e•Δφ=e•E•d E= ΔPE/e•d= 8•10⁻¹⁷/1.6•10⁻¹⁹•2.5=200N/C
October 19, 2012

Physics
m1=2250 kg, m2 =330 kg, R=550 N, a= 2 m/s² m1•a=F-R-T m2•a =T- m2•g a(m1+m2)=F-R-T+T-m2•g F= a(m1+m2) +m2•g+R=... T=m2(a+g)=…
October 19, 2012

Physics
6.00 cm
October 19, 2012

physics ..PLEASE HELP ASSIGN DUE SOON :(
k =9•10^9 N•m²/C² r=0.037m F13=k•q1•q3/r², F23=k•q2•q3/r², Cosine law for forces: F=sqrt[F13²+F23²- 2•F13•23•cos120°]
October 19, 2012

physics help
(a) T=mg =12•9.8 =... (b) F(fr)=T-mgsinα= ... (c) ma =mg-T T=m(g-a)
October 19, 2012

Physics
m•a= μ•m•g•cosα a= μ•g•cosα v=at = μ•g•cosα•t W= ΔKE=KE2-KE1 =mv²/2 -0= mv²/2
October 19, 2012

Physics
km/h -> m/s W=ΔKE=KE2-KE1=mv²/2- 0= mv²/2
October 19, 2012

Physic
Question??????
October 19, 2012

physic
mgh=mv²/2 v²=2gh, a= v²/2s=2gh/2s F=ma
October 19, 2012

Physics
W(P)=P•cosα•d=... W(fr)= - F(fr) •d= - μ•N•d = = - μ•( m•g•cosα+P•sinα) •d W(gr) = - m•g•h = - m•g•d•sin α = ...
October 19, 2012

phyics help nedded
(a) m(A)a=T1 m(B)a=m(B)g-T1+T2 m(C)a=m(C)g-T2 a{m(A) + m(B)+m(C)} = T1+ m(B)g-T1+T2 + m(C)g-T2 =g{ m(B)+m(C)} a= g{ m(B)+m(C)}/{ m(A) + m(B)+m(C)} =9.8(40+30)/(24+40+30) =7.3 m/s² T1 =m(A)a=24•7.3=175.2 N T2 = m(C)(g-a) = 30•(9.8-7.3)= 75 N (b) s=at²/2 = 7....
October 19, 2012

Physics. please help! due tomorrow!
W1=ΔKE=KE2-KE1=mv²/2- 0= mv²/2 W2 = ΔKE=KE3-KE2= =m(2v)²/2- mv²/2= 3mv²/2 =3W1
October 18, 2012

Physics- Elena please help!
Find solution in Related Questions
October 18, 2012

PHYSICS !!!!!!!!!!
E=kx²/2
October 18, 2012

Physical Science
Q=λm E=mgh Q=E λm= mgh h=λ/g = 335000/9.8 = 34184 m
October 18, 2012

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