Answer:
a. 8p
Explanation:
We are given that
Radius of hollow sphere , R1=R
Density of hollow sphere=
After compress
Radius of hollow sphere, R2=R/2
We have to find density of the compressed sphere.
We know that
Therefore,
Volume of sphere=
Using the formula
Hence, the density of the compressed sphere=
Option a is correct.
Dubnium is a synthetic element ... Number 105. It can be created
in a laboratory but it's not found in nature.
Fifteen (15) different isotopes of Dubnium have been created. They all
have 105 protons in the nucleus of every atom, but they have anywhere
from 256 to 270 neutrons in each nucleus.
The most stable isotope of Dubnium is ²⁶⁸Db , with 163 neutrons in the
nucleus. That form of Dubnium atom has a 50-50 chance of surviving
for around 28 hours before it falls apart.
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Answer:
11.8 m/s
Explanation:
At the top of the hill, there are two forces on the car: weight force pulling down (towards the center of the circle), and normal force pushing up (away from the center of the circle).
Sum of forces in the centripetal direction:
∑F = ma
mg − N = m v²/r
At the maximum speed, the normal force is 0.
mg = m v²/r
g = v²/r
v = √(gr)
v = √(9.8 m/s² × 14.2 m)
v = 11.8 m/s
Answer:
Newton's second law of motion can be formally stated as follows: The acceleration of an object as produced by a net force is directly proportional to the magnitude of the net force, in the same direction as the net force, and inversely proportional to the mass of the object.
