In accordance with the definition of density as r = m/V, in order to determine the density of
matter, the mass and the volume of the sample must be known.
The determination of mass can be performed directly using a weighing instrument.
The determination of volume generally cannot be performed directly. Exceptions to this rule
include
· cases where the accuracy is not required to be very high, and
· measurements performed on geometric bodies, such as cubes, cuboids or cylinders, the volume
of which can easily be determined from dimensions such as length, height and diameter.
· The volume of a liquid can be measured in a graduated cylinder or in a pipette; the volume of
solids can be determined by immersing the sample in a cylinder filled with water and then
measuring the rise in the water level.
Because of the difficulty of determining volume with precision, especially when the sample has a
highly irregular shape, a "detour" is often taken when determining the density, by making use of the
Archimedean Principle, which describes the relation between forces (or masses), volumes and
densities of solid samples immersed in liquid:
From everyday experience, everyone is familiar with the effect that an object or body appears to
be lighter than in air – just like your own body in a swimming pool.
Figure 3: The force exerted by a body on a spring scale in air (left) and in water (right)
- Mass of the elevator (m) = 570 Kg
- Acceleration = 1.5 m/s^2
- Distance (s) = 13 m
- Let the force be F.
- We know, F = ma,
- Therefore, F = (570 × 1.5) N = 855 N
- Angle between distance and force (θ) = 0°
- We know, work done = F s Cos θ
- Therefore, work done by the cable during this part
- = (855 × 13 × Cos 0°) J
- = (855 × 13 × 1) J
- = 11115 J
<u>Answer</u><u>:</u>
<u>1</u><u>1</u><u>1</u><u>1</u><u>5</u><u> </u><u>J</u>
Hope you could get an idea from here.
Doubt clarification - use comment section.
Answer:
The reaction force from the shaft, which keeps the wheels in place during operational rotation
Explanation:
The pinwheel design which has the same principle of a turbine, relies on a external energy source such as the wind or water to provide motive force for spinning
Whereby the reaction force provided by the shaft holding the wheel is non existent or insufficient, the wind will be able to push the wheel in its direction thereby giving the wheel only a net translation and no rotation.
Answer:
B. the object will begin to move
Explanation:
If energy is transferred the object will definitely change so it CANNOT be "A". If you add energy the object will have more force so it CANNOT be "C". The mass of an object can't increase just by giving an object energy so it CANNOT be "D"
Initial momentum of Kelly car towards South
Now Dominic truck momentum towards East
now since momentum is conserved
so final momentum of two cars must be same as initial momentum of two cars
so it is given as
so final momentum will be 2.67 x 10^4 kg m/s which is nearly option C
