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
elena-14-01-66 [18.8K]
3 years ago
9

A body at rest will remain at rest unless acted on by a(an) _____.

Physics
1 answer:
andrew11 [14]3 years ago
4 0
The answer is A. external, unbalanced force.
You might be interested in
Technician a says that some passenger vehicles use more than one evaporator. technician b says that some passenger vehicles use
dybincka [34]
<span>Tech A is correct. An evaporator is part of the heat exchange system in a vehicle. Sometimes vehicles will have more than one evaporator, each located in different areas of the vehicle. A condenser is part of the air conditioner system, and only one is normally required.</span>
3 0
3 years ago
A ball rolls off the edge of a table with a fairly large horizontal velocity. Which of the following statements are true? (Selec
Degger [83]

Answer:

A.The vertical velocity is constantly increasing as the ball falls.

B.The horizontal velocity does not noticeably change as the ball falls.

G.The horizontal velocity does not affect how long it will take the ball to fall to the floor.

H.The velocity vector of the ball changes as it travels through the air.

Explanation:

As the ball is projected horizontally so here the vertical component of the velocity is zero

So the time to reach the ground is given as

H = \frac{1}{2} gt^2

so we will have

t = \sqrt{\frac{2H}{g}}

so this is the same time as the ball is dropped from H height

Since there is no force in horizontal direction so its horizontal velocity will always remain constant while vertical velocity will change at constant rate which is equal to acceleration due to gravity.

So overall the velocity vector will change due to net acceleration g

4 0
3 years ago
On a certain planet, which is perfectly spherically symmetric, the free-fall acceleration has magnitude g = go at the north pole
ohaa [14]
The reason why there is a difference between free-fall acceleration is a centrifugal force.
I attached a diagram that shows how this force aligns with the force of gravity.
From the diagram we can see that:
F=F_g-F_{cf}=mg'-mw^2r'cos(\alpha)\\ ma=mg'-mw^2r'cos(\alpha)\\ a=g'-w^2rcos^2(\alpha)\\
Where g' is the free-fall acceleration when there is no centrifugal force, r is the radius of the planet, and w is angular frequency of planet's rotation. \alpha is the latitude.
We can calculate g' and wr^2 from the given conditions in the problem.
g(90)=g_0;\ g_0= g'-w^2rcos^2(90)\\&#10;g_0=g'\\&#10;g(0)=ag_0;\ ag_0=g_0-w^2rcos^2(0)\\&#10;ag_0=g_0-w^2r\\&#10;w^2r=g_0(a-1)&#10;
Our final equation is:
g=g_0-g_0(a-1)cos^2(\alpha)
Colatitude is:
\alpha_c=90^\circ-\alpha
The answer is:
g=g_0-g_0(a-1)cos^2(90-9)=g_0-g_0(a-1)sin^2(9)

5 0
3 years ago
A submarine is stranded on the bottom of the ocean with its hatch 21.0 m below the surface. calculate the force (in n) needed to
Tanzania [10]

Answer:

28,400 N

Explanation:

Let's start by calculating the pressure that acts on the upper surface of the hatch. It is given by the sum of the atmospheric pressure and the pressure due to the columb of water, which is given by Stevin's law:

p_{top} = p_{atm} + \rho g h=1.013\cdot 10^5 Pa + (1000 kg/m^3)(9.8 m/s^2)(21.0 m)=3.071 \cdot 10^5 Pa

On the lower part of the hatch, there is a pressure equal to

p_{bot}=p_{atm}=1.013\cdot 10^5 Pa

So, the net pressure acting on the hatch is

p=p_{top}-p_{bot}=3.071 \cdot 10^5 Pa - 1.013\cdot 10^5 Pa=2.058 \cdot 10^5 Pa

which acts from above.

The area of the hatch is given by:

A=\pi r^2 = \pi (\frac{0.420 m}{2})^2=0.138 m^2

So, the force needed to open the hatch from the inside is equal to the pressure multiplied by the area of the hatch:

F=pA=(2.058\cdot 10^5 Pa)(0.138 m^2)=28,400 N

8 0
3 years ago
HELP PLEASED THIS IS DUE TODAY AND ALSO NO LINKS PLEASED ALSO FILES PLEASED AND THANKS&gt;
Katyanochek1 [597]

1. 2 way radio

2. radio waves

3. communication

4. convert the voltage from a transmitter into a radio signal

5. signal strength refers to the transmitter power output

6. sorry, not so sure.. Though it might be the waves.

4 0
3 years ago
Other questions:
  • The what is s measure of the number of waves that pass a point in a given amount of time
    5·2 answers
  • For study, the Earth can be divided into three parts:
    15·2 answers
  • In the 1887 experiment by Michelson and Morley, the length of each interferometer arm was 11m. The experimental limit on the mea
    11·1 answer
  • A motorcycle is following a car that is traveling at constant speed on a straight highway. Initially, the car and the motorcycle
    5·1 answer
  • What causes air to become less dense and rise?
    5·1 answer
  • Why don’t we feel the gravitational force of a large object such as a skyscraper semi-truck?
    15·1 answer
  • A 2.0kg mass is intally moving at a speed of 10m/s due north, when a constant
    15·1 answer
  • ____ is the study of things getting faster as they move.
    5·2 answers
  • A train is moving with a velocity of 70 km/h.
    8·1 answer
  • ...
    15·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!