The angular velocity, ω=
2π/t; t = 24 hrs = 24 x 3600 seconds = 86400 s
ω = 7.27 x 10⁻⁵
v = ωr
= 7.27 x 10⁻⁵ x 3242.8 x 1.6 x 1000 (converting miles to meters)
= 377.2 m/s
F should be 10. If The Whole top is 50cm, then we should subtract 10n and 30n which gives us 10.
Or it could be 15 if both top and bottom are 25. 10+15= 25.
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: It is both B and D
Select all that apply.
At night, thermal energy moves _____.
from space to the atmosphere
from the land to the atmosphere
from the atmosphere to the land
from the atmosphere to space
4. KE increases by a factor of 16 is the answer
<u>Explanation:</u>
Kinetic energy = (1/2)mv² = 0.5 mv²
where
m = mass, and v = velocity.
So at 15 mph,
K
E = 0.5 m (15)
² = 112.5 m
And at 60 mph,
K
E = 0.5 m (60)² = 1800 m
m is the mass, and not meters.
So, 1800 m/112. 5 m = 16
16 times the Kinetic Energy.
