1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
MariettaO [177]
2 years ago
8

Which of the following best defines speed? (3 points) a It is an object's speed at a specific point in time. b It is the distanc

e traveled by an object in a specific direction. c It is a measure of how far an object moves over a certain amount of time. d It is the total time over the distance.
Physics
1 answer:
djverab [1.8K]2 years ago
6 0

Answer:

c.

Explanation:

they are all almost correct.

c is the only fully correct option

You might be interested in
Explain how a projectile might be modified to decrease the air resistance impacting its trajectory.
Vitek1552 [10]

Answer:

Explanation:

Explain how a projectile might be modified to decrease the air resistance impacting its trajectory.

5 0
2 years ago
A roller coaster car may be approximated by a block of mass m. Thecar, which starts from rest, is released at a height h above t
elena55 [62]

Answer:

The first part can be solved via conservation of energy.

mgh = mg2R + K\\K = mg(h-2R)

For the second part,

the free body diagram of the car should be as follows:

- weight in the downwards direction

- normal force of the track to the car in the downwards direction

The total force should be equal to the centripetal force by Newton's Second Law.

F = ma = \frac{mv^2}{R}\\mg + N = \frac{mv^2}{R}

where N = 0 because we are looking for the case where the car loses contact.

mg = \frac{mv^2}{R}\\v^2 = gR\\v = \sqrt{gR}

Now we know the minimum velocity that the car should have. Using the energy conservation found in the first part, we can calculate the minimum height.

mgh = mg2R + \frac{1}{2}mv^2\\mgh = mg2R + \frac{1}{2}m(gR)\\gh = g2R + \frac{1}{2}gR\\h = 2R + \frac{R}{2}\\h = \frac{5R}{2}

Explanation:

The point that might confuse you in this question is the direction of the normal force at the top of the loop.

We usually use the normal force opposite to the weight. However, normal force is the force that the road exerts on us. Imagine that the car goes through the loop very very fast. Its tires will feel a great amount of normal force, if its velocity is quite high. By the same logic, if its velocity is too low, it might not feel a normal force at all, which means losing contact with the track.

7 0
3 years ago
A wrench is used to tighten a spark plug. If the wrench handle is 0.20m and a force of 20N is applied, what is the torque applie
Zanzabum

Torque [Nm] = Force [N] x Force arm [m]

C=F*b=20*0.20=4 Nm

The correct answer is C


4 0
3 years ago
Jonathan has six strings that are the same thickness and are all the same material. He cuts the strings to different lengths and
harkovskaia [24]
The shortest string will have the highest pitch.

7 0
3 years ago
Read 2 more answers
estion: Why is it important to use vector quantities and not just scalar quantities to describe the motion of an object? Vector
Vera_Pavlovna [14]

Answer:

Vector quantities are important in the study of motion. Some examples of vector quantities include force, velocity, acceleration, displacement, and momentum. The difference between a scalar and vector is that a vector quantity has a direction and a magnitude, while a scalar has only a magnitude. Vector, in physics, a quantity that has both magnitude and direction. It is typically represented by an arrow whose direction is the same as that of the quantity and whose length is proportional to the quantity's magnitude. A quantity which does not depend on direction is called a scalar quantity. Vector quantities have two characteristics, a magnitude and a direction. The resulting motion of the aircraft in terms of displacement, velocity, and acceleration are also vector quantities. A vector quantity is different to a scalar quantity because a quantity that has magnitude but no particular direction is described as scalar. A quantity that has magnitude and acts in a particular direction is described as vector.

Explanation:

8 0
3 years ago
Other questions:
  • What is process that involves the collection of information and ideas supported by belief or opinion for science?
    6·1 answer
  • What is the formula for force?
    9·1 answer
  • A ship, carrying freshwater to a desert island in the caribbean, has a horizontal cross-sectional area of 2800 m2 at the waterli
    11·1 answer
  • 7. A neutral aluminum rod is at rest on a foam insulating base. A negatively charged balloon is brought near one end of the rod
    14·1 answer
  • Plzzzzzzz help me quick
    11·1 answer
  • Which characteristic is related to kinetic energy but not potential energy?
    5·1 answer
  • Microwaves have a _________wavelength and _________frequency than radio waves.
    12·2 answers
  • A.) Determine the work done by Zach on the bull.
    15·1 answer
  • Match each vocabulary word with the correct definition. 1. measure of how quickly velocity is changing 2. speed in a given direc
    7·2 answers
  • Calculate the lowest energy (in ev) for an electron in an infinite well having a width of 0.050 mm.
    10·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!