Exact numbers need not be measured. They can be counted. Conversion factors and countable units come under exact numbers. Measured quantities are measured using a device.
1) Number of microseconds in a week -Exact as it need not be measured. It can be estimated using the conversion factors between microseconds, seconds, minutes, hours, days and week.
2) Number of inches in a mile - Exact number as it is an established conversion factor.
3) The mass of a paper clip - Measured number as it has to measured using a weighing balance.
4) The number of pages in a book - Exact number as it is not measured. It can be counted.
5) Surface area of the dime-Measured number as it has to be measured.
6) The number of ounces in a pound-Exact number as it is a constant value.
Answer:
The fourth one.
Explanation:
The fourth graph shows an object speeding up ( accelerating ) coz the velocity (tangent at the curve ) at every point is different, hence denoting an acceleration.
Answer: The correct answer is option "The mechanical energy is conserved".
Explanation:
Mechanical energy = Kinetic energy + Potential Energy
Mechanical energy of the body is defined a sum of potential energy and kinetic energy possessed by the body in motion. It is the energy associated with position and motion of the body.
The principle of Conservation of Mechanical Energy states that the mechanical energy of the body remains constant as long as the forces acting on the body are conservative forces.
From, this we can say that mechanical energy of the bowling ball with mass of 2 kg falling at speed of 4.4 m/s will remain conserved.
Hence,the correct answer is "The mechanical energy is conserved".
I believe it lies in the 3rd Quadrent
It is D because nitrate reacts with the calcium and since na has a 2+ charge and no3 has a - charge we need 2 no3 to balance out the charge hence a 2 is placed outside the no3 bracket.