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
umka21 [38]
3 years ago
7

What runs all the way around the house but never moves?

Physics
2 answers:
Ainat [17]3 years ago
8 0
The answer to the question is a fence, because it goes all the way around the house but once it is there it never moves :)

amm18123 years ago
6 0
<span>A fence runs all the way around the house but never moves.</span>
You might be interested in
A bowling ball of 35.2 kg, generates 218 kg* m/s units of momentum. What is the velocity of the ball?
Aleonysh [2.5K]

Answer:

6.19 m/s

Explanation:

p = mv \\ 218 = (35.2)(v ) \\ v = 6.19 \: ms {}^{ - 1}

7 0
3 years ago
vA 61.2-kg circus performer is fired from a cannon that is elevated at an angle of 57.8 ° above the horizontal. The cannon uses
dsp73

Answer:

The effective spring constant of the firing mechanism is 1808N/m.

Explanation:

First, we can use kinematics to obtain the initial velocity of the performer. Since we know the angle at which he was launched, the horizontal distance and the time in which it's traveled, we can calculate the speed by:

v_0_x=\frac{x}{t}\\ \\v_0\cos\theta=\frac{x}{t}\\\\v_0=\frac{x}{t\cos\theta}

(This is correct because the horizontal motion has acceleration zero). Then:

v_0=\frac{20.8m}{(2.60s)\cos57.8\°}\\\\v_0=15.0m/s

Now, we can use energy to obtain the spring constant of the firing mechanism. By the conservation of mechanical energy, considering the instant in which the elastic band is at its maximum stretch as t=0, and the instant in which the performer flies free of the bands as final time, we have:

E_0=E_f\\\\U_e=K\\\\\frac{1}{2}kx^2=\frac{1}{2}mv^2\\\\\implies k=\frac{mv^2}{x^2}

Then, plugging in the given values, we obtain:

k=\frac{(61.2kg)(15.0m/s)^2}{(2.76m)^2}\\\\k=1808N/m

Finally, the effective spring constant of the firing mechanism is 1808N/m.

3 0
3 years ago
The electrons in the beam of a television tube have a kinetic energy of 2.20 10-15 j. initially, the electrons move horizontally
dalvyx [7]
(a) The electrons move horizontally from west to east, while the magnetic field is directed downward, toward the surface. We can determine the direction of the force on the electron by using the right-hand rule:
- index finger: velocity --> due east
- middle finger: magnetic field --> downward
- thumb: force --> due north
However, we have to take into account that the electron has negative charge, therefore we have to take the opposite direction: so, the magnetic force is directed southwards, and the electrons are deflected due south.

b) From the kinetic energy of the electrons, we can find their velocity by using
K= \frac{1}{2}mv^2
where K is the kinetic energy, m the electron mass and v their velocity. Re-arranging the formula, we find
v= \sqrt{ \frac{2K}{m} }= \sqrt{ \frac{2 \cdot 2.20 \cdot 10^{-15} J}{9.1 \cdot 10^{-31} kg} }=6.95 \cdot 10^7 m/s

The Lorentz force due to the magnetic field provides the centripetal force that deflects the electrons:
qvB = m \frac{v^2}{r}
where
q is the electron charge
v is the speed
B is the magnetic field strength
m is the electron mass
r is the radius of the trajectory
By re-arranging the equation, we find the radius r:
r= \frac{mv}{qB}= \frac{(9.1 \cdot 10^{-31} kg)(6.95 \cdot 10^7 m/s)}{(1.6 \cdot 10^{-19} C)(3.00 \cdot 10^{-5} T)}=13.18 m

And finally we can calculate the centripetal acceleration, given by:
a_c =  \frac{v^2}{r}= \frac{(6.95 \cdot 10^7 m/s)^2}{13.18 m}=3.66 \cdot 10^{14} m/s^2
5 0
3 years ago
If a 75 W lightbulb is 15% efficient, how many joules of light energy does the bulb produce every minute?
stiks02 [169]

Answer:

1 W = 1 J / sec       Definition of watt is 1 joule / sec

So if a bulb uses 75 J / sec it must use

75 J/s * 60 sec / min = 4500 J/min    energy used by bulb

If bulb is 15% efficient then the light delivered is

P = 4500 J / min * .15 = 675 J / min

4 0
2 years ago
Two students make the following claims:
antiseptic1488 [7]

Answer:

E. Student 1 is correct, because as θ is increased, h is the same.

Explanation:

Here we have the object of a certain mass falling under gravity so the force acting on the it will depend on mass of the object and the acceleration due to gravity.

Mathematically:

F=m.g

As we know that the work done is evaluated as the force applied on a body and the displacement of the body in the direction of the force.

And for work we have:

W=F.s\cos\theta

where:

s= displacement of the object

\theta= angle between the force and displacement vectors

Given that the height of the object is same in each trail of falling object under the gravity be it a free-fall or the incline plane.

  • In case of free-fall the angle between the force is and the displacement is zero.
  • In case when the body moves along the inclined plane the force applied by the gravity is same because it depends upon the mass of the object. And the net displacement in the direction of the gravitational force is the height of the object which is constant in both the cases.

So, the work done by the gravitational force is same in the two cases.

6 0
3 years ago
Other questions:
  • Determine the displacement of a plane that is uniformly accelerated from 66 m/s to 88 m/s in 12 s
    5·1 answer
  • What caused people to accept the geocentric model of the universe?
    15·1 answer
  • What is the work done by a car's braking system when it slows the 1500-kg car from an initial speed of 96 km/h down to 56 km/h i
    14·2 answers
  • A 0.2kg mass attached to the end of a spring is whirled in a vertical circle by a student. At some position, the mass experience
    12·1 answer
  • Several motorboats with the same mass are used in an experiment. The forces of the different motors versus their accelerations a
    8·1 answer
  • Every force has one and only one 3rd law pair force.
    12·2 answers
  • И СРСct to
    6·1 answer
  • 5. Atoms may emit light energy when
    7·1 answer
  • Why is the fuse used in a circuit called safety fuse?<br>​
    5·2 answers
  • Explain whether a particle moving in a straight line with constant speed does or does not have an acceleration. b) Explain wheth
    8·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!