Answer:
0.75
Explanation:
Since the static frictional force is the maximum force applied just before sliding, our frictional force, F is 300 N.
Since F = μN where μ = coefficient of static friction and N = normal force = 400 N (which is the downward force applied against the surface).
So, μ = F/N
= 300 N/400 N
= 3/4
= 0.75
So, the coefficient of static friction μ = 0.75
The centripetal acceleration is given by
where v is the tangential speed and r the radius of the circular orbit.
For the car in this problem,
and r=40 m, so we can re-arrange the previous equation to find the velocity of the car:
Answer:
Wn = 9.14 x 10¹⁷ N
Explanation:
First we need to find our mass. For this purpose we use the following formula:
W = mg
m = W/g
where,
W = Weight = 675 N
g = Acceleration due to gravity on Surface of Earth = 9.8 m/s²
m = Mass = ?
Therefore,
m = (675 N)/(9.8 m/s²)
m = 68.88 kg
Now, we need to find the value of acceleration due to gravity on the surface of Neutron Star. For this purpose we use the following formula:
gn = (G)(Mn)/(Rn)²
where,
gn = acceleration due to gravity on surface of neutron star = ?
G = Universal Gravitational Constant = 6.67 x 10⁻¹¹ N.m²/kg²
Mn = Mass of Neutron Star = Mass of Sun = 1.99 x 10³⁰ kg
Rn = Radius of neutron Star = 20 km/2 = 10 km = 10000 m
Therefore,
gn = (6.67 x 10⁻¹¹ N.m²/kg²)(1.99 x 10³⁰ kg)/(10000)
gn = 13.27 x 10¹⁵ m/s²
Now, my weight on neutron star will be:
Wn = m(gn)
Wn = (68.88)(13.27 x 10¹⁵ m/s²)
<u>Wn = 9.14 x 10¹⁷ N</u>
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.
