Explanation:
Principle focus is the point on the axis of a convex lens, where the parallel rays of light from one side of the lens. meet on other side after refraction. Distance between optical centre to principle focus point is the focal length.
10800 m = 10.8 km should be the answer if I am correct
Answer:
The linear velocity is 
Explanation:
According to the law of conservation of energy
The potential energy possessed by the hoop at the top of the inclined plane is converted to the kinetic energy at the foot of the inclined plane
The kinetic energy can be mathematically represented as
Where 
is the moment of inertia possessed by the hoop which is mathematically represented as
Here R is the radius of the hoop
is the angular velocity which the hoop has at the bottom of the lower part of the inclined plane which is mathematically represented as
Where v linear speed of the hoop's center of mass just as the hoop leaves the incline and rolls onto a horizontal surface
Now expressing the above statement mathematically
=> 
=> 
=> 
=> 
Substituting values
Answer:
c large, spherical body that orbits in a clear path around a star
Explanation:
you can not say b because the sun is a star and you cant say a and d because all planets are not made of rock and all planets are not made of gas
Answer:
3.6 KJ
Explanation: Given that a 70-kg boy is surfing and catches a wave which gives him an initial speed of 1.6 m/s. He then drops through a height of 1.60 m, and ends with a speed of 8.5 m/s. How much nonconservative work (in kJ) was done on the boy
The workdone = the energy.
There are two different energies in the scenario - the potential energy (P.E ) and the kinetic energy ( K.E )
P.E = mgh
P.E = 70 × 9.8 × 1.6
P.E = 1097.6 J
P.E = 1.098 KJ
K.E = 1/2mv^2
K.E = 1/2 × 70 × 8.5^2
K.E = 2528.75 J
K.E = 2.529 KJ
The non conservative workdone = K.E + P.E
Work done = 1.098 + 2.529
Work done = 3.63 KJ
Therefore, the non conservative workdone is 3.6 KJ approximately
