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1 year ago

The refractive index of glass is 1.65 find the speed of light in glass.

1 answer:

3 0

The refractive index of flint glass is 1.65.what is the speed of light in the glass? speed of light in the air is 3 x 10 power 8 m/s

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you are flying a kite that has two strings attached to either side of it you are holding those strings in your left and right ha

Svetach [21]

The kite would move to the right as well

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1 year ago

Read 2 more answers

If you are driving 72 km/h along a straight road and you look to the side for 4.0 s, how far do you travel during this inattenti

Ann [662]

We know that speed equals distance between time. Therefore to find the distance we have that d = V * t. Substituting the values d = (72 Km / h) * (1h / 3600s) * (4.0 s) = 0.08Km.Therefore during this inattentive period traveled a distance of 0.08Km

8 0

2 years ago

A bar of silicon is 4 cm long with a circular cross section. If the resistance of the bar is 270 ω at room temperature, what is

vova2212 [387]

solution:

$consider the following data\\
length of slicon bar with circular cross section is 4cm or 0.04m\\
at room temperature resistance of the slicon bar is 270\Omega \\
represent the resistance in mathematical from\\
r=p\frac{1}{A}---1\\
where r is resistance and l is the length \\
A is cross sectional area\\
it is clear that resistivity of the silicon meterial is 6.4\times^2 \Omega.m\\
substitute 6.4\times10^2 for p,270\Omega for R and 0.04m for l i equation (1).\\$ $270=(604\times10^2)\frac{0.04}{A}\\
rewrite the equation\\
a=(6.4\times10^2)\frac{(0.04)}{270}\\
=0.9481m^2\\
write the formula for the circular cross sectional area of silicon bar.\\
A=\pi r^2\\
substitute 0.9481 for A in the above equation\\
\pi r^2=0.9481
r^2=\frac{0.9481}{3.14},since \pi =3.14\\
0.30194\\
further simplified\\
r^2=0.30194\\
\sqrt{0.30194}\\
\cong 0.1509m\\
\cong 150.1mm$

7 0

2 years ago

A 900 kg steel beam is supported by the two ropes shown in (Figure 1) . Calculate the tension in the rope.

Rzqust [24]

Let T1 and T2 be tension in ropes1 and 2 respectively.
since system is stationary (equilibrium), considering both ropes + beam as a system 

for horizontal equilibrium (no movement in that direction, so resultant force must be zero horizontally) 
T1sin(20) = T2sin(30) 
=> T1 = T2sin(30) / sin(20) 

for vertical equilibrium, (no movement in this direction, so resultant force must be zero vertically) 
T1cos(20) + T2cos(30) = mg 

m = 900kg, substituting for T1 
T2sin(30)*cos(20)/sin(20) + T2cos(30) = 900g 
2.328*T2 = 900*9.8 
T2 = 3788.65N 
so T1 from (1) 
T1 = 5535.21N

8 0

1 year ago

A truck is traveling down a road with a 4-percent grade at a speed of 75 mi/h when its brakes are applied to slow it down to 22.

kvasek [131]

Answer:

3.964 s

Explanation:

Metric unit conversion:

1 miles = 1.6 km = 1600 m.

1 hour = 60 minutes = 3600 seconds

75 mph = 75 * 1600 / 3600 = 33.3 m/s

22.5 mph = 22.5 * 1600/3600 = 10 m/s

Let g = 9.81 m/s2

Friction is the product of coefficient and normal force, which equals to the gravity

$F_f = \mu N = \mu mg$

The deceleration caused by friction is friction divided by mass according to Newton 2nd law.

$a = F_f / m = \mu mg / m = \mu g = 0.6 *9.81 = 5.886 m/s^2$

So the time required to decelerate from 33.3 m/s to 10 m/s so the wheels don't slide, with the rate of 5.886 m/s2 is

$t = \frac{\Delta v}{a} = \frac{33.3 - 10}{5.886} = 3.964 s$

3 0

1 year ago