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
Alla [95]
3 years ago
12

A box slides down a frictionless plane inclined at an angle θ ¸ above the horizontal. The gravitational force on the box is dire

cteda)vertically.b)perpendicular to the plane.c)at an angle θ ¸ below the inclined plane.d)parallel to the plane in the same direction as the movement of the box.e)parallel to the plane in the opposite direction as the movement of the box.

Physics
2 answers:
DedPeter [7]3 years ago
6 0
<h2>Answer: at an angle \theta below the inclined plane. </h2>

If we draw the <u>Free Body Diagram</u> for this situation (figure attached), taking into account only the gravity force in this case, we will see the weight W of the block, which is directly proportional to the gravity acceleration g:  

W=m.g

This force is directed vertically at an angle \theta below the inclined plane, this means it has an X-component and a Y-component:

W=W_{X}+W_{Y}

W_{X}=m.g.cos(\theta)

W_{Y}=m.g.sin(\theta)

Therefore the correct option is c

Alex777 [14]3 years ago
5 0

Explanation:

When a box is placed in the friction less plane inclined at an angle θ. The forces acting on the box are

1. Weight of the box, W = m g

2. Force of friction, f

3. Normal force, N

When we resolve these forces in horizontal and vertical components, we get :

N=mg\ cos\theta

f=mg\ sin\theta

We know that the direction of gravitational force is always in downward direction. So, the gravitational force on the box is directed vertically. Hence, the correct option is (a).

You might be interested in
A 1.50x103-kilogram car is traveling east at 30 meters per second.
frez [133]

Answer:

39000\ \text{kg m/s}

West

Explanation:

m = Mass of car = 1.3\times 10^{3}\ \text{kg}

t = Time = 9 seconds

u = Initial velocity = 30 m/s

v = Final velocity = 0

Impulse is given by

J=m(v-u)\\\Rightarrow J=1.3\times 10^3(0-30)\\\Rightarrow J=-39000\ \text{kg m/s}

The magnitude of the total impulse applied to the car to bring it to rest is 39000\ \text{kg m/s}.

The direction is towards west as the sign is negative.

7 0
3 years ago
Which changes in energy form are illustrated in the diagram.
Grace [21]
It would be B since it starts with the solar energy which is converted to electricity with the solar panels, which then creates mechanical energy for the fans blades to move and sound for the radio.

Hope that helps :)
6 0
3 years ago
What do astronomers use in addition to parallax to find the actual distance of stars that are close to Earth?
IgorLugansk [536]

Answer:

trigonometry (guessing)

Explanation:

ellipse: is the shape of an orbit : looks like an oval

periapsis : shortest distance between something like the moon and the planet its orbiting around like the earth

parallax is triangulation. like how gps works. looking at a star one day and then looking at it again 6 months later, an astronomer can see a difference in the viewing angle for the star. With trigonometry, the different angles yield a distance. This technique works for stars within about 400 light years of earth

https://science.howstuffworks.com/question224.htm

By comparing the intrinsic brightness to the star's apparent brightness we can calculate the distance of stars

1/r^2 rule states that the apparent brightness of a light source is proportional to the square of its distance.Jan 11, 2022

https://www.space.com/30417-parallax.html

alternative distance measurement for stars used by most astronomers is the parsec. A star with a parallax angle of 1 arcsecond has a distance of 1 parsec, or 1 parsec per arcsecond of parallax, which is about 3.26 light years

blossoms.mit.edu

.

7 0
2 years ago
A 45.0-kg girl is standing on a 168-kg plank. The plank, originally at rest, is free to slide on a frozen lake, which is a flat,
muminat

Answer:

The speed of the plank relative to the ice is:

v_{p}=-0.33\: m/s

Explanation:

Here we can use momentum conservation. Do not forget it is relative to the ice.

m_{g}v_{g}+m_{p}v_{p}=0 (1)

Where:

  • m(g) is the mass of the girl
  • m(p) is the mass of the plank
  • v(g) is the speed of the girl
  • v(p) is the speed of the plank

Now, as we have relative velocities, we have:

v_{g/b}=v_{g}-v_{p}=1.55 \: m/s (2)

v(g/b) is the speed of the girl relative to the plank

Solving the system of equations (1) and (2)

45v_{g}+168v_{p}=0

v_{g}-v_{p}=1.55

v_{p}=-0.33\: m/s

I hope it helps you!      

8 0
3 years ago
In free fall the object with less air resistance falls with a greater acceleration
ANEK [815]

terminal velocity ... greater speed ... acc is 10m/s/s

5 0
3 years ago
Other questions:
  • Two soccer players kick the same 1-kg ball at the same time in opposite directions. one kicks with a force of 20 n; the other ki
    8·2 answers
  • What are the three things a chloroplast needs in order to complete photosynthesis?
    14·1 answer
  • Write the law of conservation of energy. How does it apply to eating and exercising?
    5·1 answer
  • A 1 530-kg automobile has a wheel base (the distance between the axles) of 2.70 m. The automobile's center of mass is on the cen
    13·1 answer
  • Mike has a mass of 97 kg. He jumps out of a perfectly good airplane that is 2000 m above the ground. After he falls 1000 m, when
    12·1 answer
  • Assume the average value of the vertical component of Earth's magnetic field is 42 μT (downward) in some region that has an area
    14·1 answer
  • A two-stage rocket moves in space at a constant velocity of +4300 m/s. The two stages are then separated by a small explosive ch
    10·1 answer
  • In which era did the universe’s clouds start to condense and the universe became transparent for the first time?
    9·1 answer
  • If a car starts from rest and attains a velocity of 10m/square in 5 secondscalculate the accerleration​
    14·2 answers
  • A plane is flying to Minnesota with a velocity of 277.73 km/h, N. The plane
    15·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!