A)
The moon orbiting the Earth
The answer is D because instantaneous means at a particular point in time
Answer:
The answer is 0.8 m
Explanation:
According the attached diagram, if we take the momentum in the point 0:

Where
mD = mass of Diane = 64.2 kg
mJ = mass of Jack = 93.6 kg
Replacing:


Answer:
The false statement is in option 'd': The center of mass of an object must lie within the object.
Explanation:
Center of mass is a theoretical point in a system of particles where the whole mass of the system is assumed to be concentrated.
Mathematically the position vector of center of mass is defined as

where,
is the position vector of the mass dm.
As we can see for homogenous symmetrical objects such as a sphere,cube,disc the center of mass is located at the centroid of the shapes itself but in many shapes it is located outside the body also.
Examples of shapes in which center of mass is located outside the body:
1) Horseshoe shaped body.
2) A thin ring.
In many cases we can make shapes of bodies whose center of mass lies outside the body.
Answer:NO
Explanation:
No the mold should not be of the same size as that of sculpture because the material from which molds is made may shrink or expand depending upon its properties .
For example grey cast iron shrinks on cooling.
We need to make mold bigger in general so that if there is a need of finishing it can be done easily without altering the size of sculpture.