Answer:
Option d is correct.
Explanation:
We know , resistance of a body is directly proportional to its length and inversely proportional to its area.
( Here, 
is constant dependent on object material )
Writing 
also :
( since they are of same material therefore, is same.)
Now , if 
.
Then 
Therefore, option d. is correct.
Hence, this is the required solution.
Answer:
d. the same within the uncertainty of each measurement method
Explanation:
The density of an object and in general any physical property, has the same value regardless of the method used to measure it, either directly or indirectly. Since two completely different valid methods are used, the results must be the same, taking into account the level of precision of each of the methods.
Answer:
Explanation:
Total energy is constant
E = mgh + ½mv² + Fd
At the top of the slide, all energy is potential
E = mgh + 0 + 0
At the bottom of the slide, all potential energy has converted to kinetic and work of friction.
mgh = ½mv² + W
W = mgh - ½mv²
W = 30.0[(9.81)(2.0) - ½6²]
W = 48.6 J
