Answer:
Option 3. The tennis ball began from rest and rolls at a rate of 14.7 m/s safer 1.5 seconds.
Explanation:
To know the the correct answer to the question, it is important that we know the definition of acceleration.
Acceleration can simply be defined as the rate of change of velocity with time. Mathematically, it is expressed as:
a = (v – u) /t
Where
a => acceleration
v => final velocity
u => Initial velocity
t => time
With the above information in mind, let us consider the options given in the question above to know which conform to the difinition of acceleration.
For Option 1,
We were told that the tennis ball has the following:
Distance = 4 m
Time = 1.5 s
This talks about the speed and not the acceleration.
Speed = distance / time
For Option 2,
We were only told about the average speed and nothing else.
For Option 3,
We were told that the tennis ball have the following:
Initial velocity (u) = 0 m/s
Final velocity (v) = 14.7 m/s
Time = 1.5 s
This talks about the acceleration.
a = (v – u) /t
For Option 4,
We were only told that the tennis rolls to the right at an average speed. This talks about the average velocity. We need more information like time to justify the acceleration.
From the above illustrations, option 3 gives the correct answer to the question.
Answer:
<h2>
The answer is </h2><h2>
a. 5g/mL</h2>
Explanation:
Given data
mass m= 45g
volume v= 9mL
we know that density=m/v
substituting our given data we have
What is Density?
The Density of a body can be defined as the ratio of mass to volume,
or
Density, mass of a unit volume of a material substance. The formula for density is 
,
where d is density,
M is mass, and
V is volume.
Density is commonly expressed in units of grams per cubic centimetre.
There are two equal forces of gravity between the Earth and the Moon.
One force pulls the Moon toward the Earth.
The other force pulls the Earth toward the Moon.
If only this gravity suddenly switched off, then the moon would
continue to orbit the Sun, very much as it does now.
If ALL gravity suddenly switched off, then . . .
-- the Moon would stop orbiting the Earth and would sail away, in
a straight line and at the speed it had when gravity disappeared;
-- the Earth would stop orbiting the Sun and would sail away, in
a straight line and at the speed it had when gravity disappeared;
-- all the gases surrounding the Earth ... which we call "air" ... would
start drifting away, and expanding into a giant cloud of gas, and stop
being an atmosphere;
-- the Sun would completely fall apart, expand into a giant cloud of gas,
and stop being a star.
