answer.
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
astra-53 [7]
2 years ago
11

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.

Physics
2 answers:
Aloiza [94]2 years ago
8 0

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:

F=ma

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.

MrRissso [65]2 years ago
3 0

Answer:

I’s B

Explanation:

You might be interested in
A champion athlete can produce one horsepower (746 W) for a short period of time. The number of 16-cm-high steps a 70-kg athlete
erastovalidia [21]

Answer:

407 steps

Explanation:

From the question,

P = mgh/t........... Equation 1

Where P = power, m = mass, g = acceleration due to gravity, h = height, t = time.

Make h the subject of the equation

h = Pt/mg............. Equation 2

Given: P = 746 W, t = 1 minute = 60 seconds, m = 70 kg.

Constant: g = 9.8 m/s²

Substitute into equation 2

h = 746(60)/(70×9.8)

h = 44760/686

h = 65.25 m

h = 6525 cm

number of steps = 6525/16

number of steps = 407 steps

6 0
2 years ago
Mary takes 6.0 seconds to run up a flight of stairs that is 102 meters long. if mary's weight is 87 newtons, what power has mary
pentagon [3]
Thank you for posting your question here at brainly. I hope the answer will help. Below are the choices that can be found elsewhere:

 <span>A. 1.5 * 10^3 Watts 
B. 7.3 * 10^2 Watts 
C. 3.5 * 10^2 Watts 
D. 2.5 * 10^2 Watts
</span>
 <span>Work = force*displacement = 10^2*87 = 8,700 joule 
Power = work/time = 8,700/6 = 1.45*10^3 (rounded up to 1.5 kw). The answer is A. </span>
3 0
2 years ago
Read 2 more answers
A mass is tied to a string and swung in a horizontal circle with a constant angular speed. show answer No Attempt If this speed
Liono4ka [1.6K]

Answer:

The tension in the string is quadrupled i.e. increased by a factor of 4.

Explanation:

The tension in the string is the centripetal force. This force is given by

F = \dfrac{mv^2}{r}

m is the mass, v is the velocity and r is the radius.

It follows that F \propto v^2, provided m and r are constant.

When v is doubled, the new force, F_1, is

F_1 = \dfrac{m(2v)^2}{r} = \dfrac{4mv^2}{r} = 4\dfrac{mv^2}{r} = 4F

Hence, the tension in the string is quadrupled.

8 0
2 years ago
During the 440, a runner changes his speed as he comes out of the curve onto the home stretch from 18 ft/sec to 38 ft/sec over a
Sloan [31]

Answer:

6.67ft/s^2

Explanation:

We are given that

Initial velocity=u=18ft/s

Final velocity,v=38ft/s

Time=t=3 s

We have to find the average acceleration over that 3 s period.

We know that

Average acceleration,a=\frac{v-u}{t}{t}

Using the formula

Average acceleration,a=\frac{38-18}{3}ft/s^2

Average acceleration,a=\frac{20}{3}ft/s^2

Average acceleration,a=6.67ft/s^2

Hence, the average acceleration=6.67ft/s^2

5 0
2 years ago
The diagram shows movement of thermal energy. At bottom a fire has red curved lines labeled Y with arrowheads pointing upward to
Pepsi [2]

Answer:

X and Z

Explanation:

Conduction occurs through direct physical contact.  Heat transferred from the pot to the handle, and from the handle to the hand, are both examples of conduction.

6 0
2 years ago
Read 2 more answers
Other questions:
  • Scientists in a test lab are testing the hardness of a surface before constructing a building. Calculations indicate that the en
    15·1 answer
  • A hockey puck with a mass of 0.16 kg is sitting at rest on a frozen pond. Suddenly, the wind begins to blow, accelerating the pu
    6·2 answers
  • A sample of gas has a volume of 215 cm3 at 23.5 °c and 84.6 kpa. what volume (cm3 will the gas occupy at stp
    12·1 answer
  • You use energy to heat your home. what ultimately happens to the energy that you pay for in your heating bill?
    14·2 answers
  • Vectors a and b have scalar product â6.00, and their vector product has magnitude +9.00. what is the angle between these two vec
    5·1 answer
  • A horizontal jet of water is made to hit a vertical wall with a negligible rebound. If the speed of water from the jet is 'v', t
    13·1 answer
  • A transmission channel is made up of three sections. The first section introduces a loss of 16dB, the second an amplification (o
    12·1 answer
  • You and your friend Peter are putting new shingles on a roof pitched at 20degrees . You're sitting on the very top of the roof w
    5·1 answer
  • Finally, you are ready to answer the main question. Cheetahs, the fastest of the great cats, can reach 50.0 miles/hourmiles/hour
    8·1 answer
  • 1. A city bus travels 6 blocks east and 8 blocks north. Each block is 100 m long. If the bus travels this distance in 15mins, wh
    13·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!