Which of the following are inertial reference frames? A. A car driving at steady speed on a straight and level road. B. A car dr
iving at steady speed up a 10∘ incline. C. A car speeding up after leaving a stop sign. D. A car driving at steady speed around a curve.
2 answers:
Answers:
A. A car driving at steady speed on a straight and level road.
B. A car driving at steady speed up a 10∘ incline.
Explanation:
An object is said to be in an inertial reference frame if the net force acting on the object is zero. According to Newton's second law, this also means that the acceleration of the object is also zero:
Since F=0, a=0 as well.
Let's now analyze each case.
A. A car driving at steady speed on a straight and level road. --> YES: this is an inertial reference frame, because the car is keeping a constant speed and a constant direction, so its velocity is not changing, and its acceleration is zero.
B. A car driving at steady speed up a 10∘ incline. --> YES: this is an inertial reference frame, because the car is keeping a constant speed and a constant direction, so its velocity is not changing, and its acceleration is zero.
C. A car speeding up after leaving a stop sign. --> NO: this is not an intertial reference frame, because the car is speeding up, so it is accelerating.
D. A car driving at steady speed around a curve. --> NO: this is not an inertial reference frame, because the car is changing direction, therefore its velocity is changing and so the car is accelerating.
So the only two choices which are correct are A and B.
You might be interested in
Answer:
The rotational inertia of the pendulum around its pivot point is .
Explanation:
The angular frequency of a physical pendulum is measured by the following expression:
Where:
- Angular frequency, measured in radians per second.
- Mass of the physical pendulum, measured in kilograms.
- Gravitational constant, measured in meters per square second.
- Straight line distance between the center of mass and the pivot point of the pendulum, measured in meters.
- Moment of inertia with respect to pivot point, measured in
.
In addition, frequency and angular frequency are both related by the following formula:
Where:
- Frequency, measured in hertz.
If , then angular frequency of the physical pendulum is:
From the formula for the physical pendulum's angular frequency, the moment of inertia is therefore cleared:
Given that ,
,
and
, the moment of inertia associated with the physical pendulum is:
The rotational inertia of the pendulum around its pivot point is .
Answer:
<em>Magnitude of A=5</em>
<em>Magnitude of B=5.39</em>
Explanation:
<u>The magnitude of Vectors in Rectangular Form</u>
Given a vector v in its rectangular form:
The magnitude of v is:
We are given the vectors
Their magnitudes are: