Answer:
Explanation:
For entry of light into tube of unknown refractive index
sin ( 90 - 25 ) / sinr = μ , μ is the refractive index of the tube , r is angle of refraction in the medium of tube
r = 90 - C where C is critical angle between μ and body medium in which tube will be inserted.
sin ( 90 - 25 ) / sin( 90 - C) = μ
sin65 / cos C = μ
sinC = 1.33 / μ , where 1.33 is the refractive index of body liquid.
From these equations
sin65 / cos C = 1.33 / sinC
TanC = 1.33 / sin65
TanC = 1.33 / .9063
TanC = 1.4675
C= 56°
sinC = 1.33 / μ
μ = 1.33 / sinC
= 1.33 / sin56
= 1.33 / .829
μ = 1.6 Ans
Answer:
Explanation:
a )
change in the gravitational potential energy of the bear-Earth system during the slide = mgh
= 45 x 9.8 x 11
= 4851 J
b )
kinetic energy of bear just before hitting the ground
= 1/2 m v²
= .5 x 45 x 5.8²
= 756.9 J
c ) If the average frictional force that acts on the sliding bear be F
negative work done by friction
= F x 11 J
then ,
4851 J - F x 11 = 756.9 J
F x 11 = 4851 J - 756.9 J
= 4094.1 J
F = 4094.1 / 11
= 372.2 N
Explanation:
Below is an attachment containing the solution.
<u>Answer</u>
To increase friction for a better grip.
<u>Answer</u>
Most human beings do sweat hands especially on the palm. When this happens the person will not have a good grip of heavy objects because they will slide/slip from the hand.
<em>By applying the powder, you are trying to make the hand dry hence increasing the friction for a better grip. </em>
If the gymnast doesn't do this the parallel bars may slip from the hands and injure himself or herself.
Answer:
11.95m/s
Explanation:
A moving object has a kinetic energy of 150 J and a momentum of 25.1 kg·m/s.
a) Find the speed of the object. Answer in units of m
K. E =½mv²
150= ½mv²
Multiply both sides by 2
mv² = 300
Divide both sides by v²
m = 300/v² .................. Equation 1
Momentum is the product of mass and velocity
Momentum = mv
25.1 = mv
Divide both sides by v
m = 25.1/v ................ Equation 2
Equate equations 1 and 2
300/v² = 25.1/v
Cross multiply
25.1v² = 300v
Multiply v with both sides
25.1v = 300
Divide both sides by 25.1
v = 300/25.1
V = 11.95m/s
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