Answer:
Explanation:
As we know that current density is ratio of current and area of the crossection
now we have
so the current through the wire is given as
now we have
here we have
now plug in the values in above equation
now we have
now plug in both limits as mentioned
here R = 2.11 mm
The answer is t<span>he phosphoric acid in cola easily removes dirt and grime. The </span>"cola" type drinks is suitable to polish chrome surfaces. Cola contains a very diluted solution of phosphoric acid, which can remove rust, dirt, and grime from chrome surface.
Answer:
Time to reach maximum height can be obtained from v=u+at
0=20+(−10)t
t=2s
s=ut+0.5at
2
=20(2)+0.5(−10)(2)
2
=20m
Thus, total distance for maximum height is 45 m
s=ut+0.5at
2
45=0+0.5(10)(t ′ )
2
t
′
=3s
Total time= 3+2= 5s
Explanation:
TAKE 22.0 IN PLACE OF 20 U WILL GET YR ANSWER
HOPE IT HELPS
Answer:
B. 3
Explanation:
The half-life of a radioisotope is the time it needs for the mass of the radioisotope to halve with respect to its original value.
In this problem, the initial mass of the radioisotope at t=0 is
m0 = 50.0 mg
We see that after t = 1 min, the mass of the isotope is
m(1 min) = 25.0 mg
so, exactly half the initial mass: this means that 1 minute is exactly the half-life of this radioisotope.
So, the amount of mass left after each minute is the following:
m (1 min ) = 25.0 mg (1 half-life)
m (2 min) = 12.5 mg (2 half-lives)
m (3 min) = 6.25 mg (3 half-lives)
so, when we are left with 6.25 mg of isotope, 3 minutes have passed, which means that 3 half-lives have passed.
Answer: The focal length of the cornea-lens system in his eye must be LESS THAN the distance between the front and back of his eye.
Explanation:
The human eye the front part of the eye is the CORNEA. This is the tough white transparent part of the eye that helps in the refraction of light rays. While the backside of the eye is the RETINA. This is the part of the eye when images are focused.
When a normal eye is at rest, parallel rays from a distant object are focused on the retina. The ability of the eye - lens to focus points at different distances on the retina is known as accomodation. The adjustment of the eye lens to focus objects of varying distances is brought about by the ciliary muscles. The have the ability to change the shape of the eye which leads to change in focal length.
When a person with normal vision looks at a distant object at infinity, the lens brings parallel rays to focus on the retina. Thus, the furthest point which the eye can see distinctly is called the far point of the eye and it's infinity for a normal eye. But Joe was able to focus his eye on the tree, meaning that the tree was within his near point. This is the nearest point at which an object is clearly seen. Therefore, when the effective focal length of the cornea-lens system changes, it changes the location of the image of any object in one's field of view.
