Evidence of Chemical Change:
A car rusting
Leaves changing in October
The glow of a light bulb
A white cloudy substance occurs after mixing two substances
Burning toasts
A candle being lit
Evidence of Physical Change:
Water boiling
Yellow and blue paints mixed together
Wax melting
Crushing a rock with a hammer
Hope this helps!
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Answer:
Explanation:
The form of Newton's 2nd Law that we use for this is:
F - f = ma where F is the Force pulling the mass down the ramp forward, f is the friction trying to keep it from moving forward, m is the mass and a is the acceleration (and our unknown).
We know mass and we can find f, but we don't have F. But we can solve for that by rewriting our main equation to reflect F:
That's everything we need.
w is weight: 6.0(9.8). Filling in:
6.0(9.8)sin20 - .15(6.0)(9.8) = 6.0a and
2.0 × 10¹ - 8.8 = 6.0a and
11 = 6.0a so
a = 1.8 m/s/s
Answer:
E_total = 3 N / A
Explanation:
The electric field is a vector magnitude so when adding we must use vectors, in this case as the initial field E = 4N / c goes towards the axis axis and the field created by the fixed charge (E1) is also on the axis x we can add in scalar form.
E_total = E + E₁
the expression for the field of a point charge is
E₁ = k q₁ / r²
for the point x = 2m, they do not say that the total field is zero, so the charge q1 must be negative
E_total = E -k q₁ / r₂
we substitute
0 = E - k q₁ / r²
q₁ =
let's calculate
q₁ =
q₁ = 1.78 10⁻⁹ C
now we can calculate the field for position x = 4 m
E_total = 4 - 9 10⁹ 1.78 10⁻⁹ / 4²2
E_total = 3 N / A
Answer:
236.3 x
C
Explanation:
Given:
B(0)=1.60T and B(t)=-1.60T
No. of turns 'N' =100
cross-sectional area 'A'= 1.2 x
m²
Resistance 'R'= 1.3Ω
According to Faraday's law, the induced emf is given by,
ℰ=-NdΦ/dt
The current given by resistance and induced emf as
I = ℰ/R
I= -NdΦ/dtR
By converting the current to differential form(the time derivative of charge), we get
= -NdΦ/dtR
dq= -N dΦ/R
The change in the flux dФ =Ф(t)-Ф(0)
therefore, dq =
(Ф(0)-Ф(t))
Also, flux is equal to the magnetic field multiplied with the area of the coil
dq = NA(B(0)-B(t))/R
dq= (100)(1.2 x
)(1.6+1.6)/1.3
dq= 236.3 x
C
Answer:
scientists will use absolute dating to find how old a fossil exactly is.