tại sao trái đất lại có trọng lực

Answer:

Explanation:

1. Free fall implies an object falling under the gravitational influence only. During the flight, no other force acts on it except the gravitational pull.

2. Acceleration due to gravity is the earth's natural force of pull on all objects on its surface, close to its surface, or in the region where the force can be felt. This force pulls object to the surface of the earth.

3. Escape velocity is the required minimum velocity for an object to leave the gravitational influence of the earth. It has a constant value which can be determined by;

Escape velocity = [tex]\sqrt{2gR}[/tex]

where g is the gravitation force of the earth and R is the radius of the earth.

4. Centripetal force is the force of pull that is required to keep a rotation object in its curved path.

Answer:

increase

Explanation:

guesshejwoowsnnsnakalalapqjhdjd

Answer:

our weight would decrease.

Explanation:

because of you burning all those calories and fat from hiking up the mountain.

Answer:

f=ma.......m=f/a......m=20kg

Answer:

The diagram assigned B

explanation:

Check the direction of the two vectors, their resultant must be in the same direction.

Answer: If we leave liquid butane in a bowl on a table in a room where the temperature is [tex]24^{o}C[/tex], butane will evaporate.

Explanation:

A temperature at which the the liquid and gaseous phase of a substance of a substance are present in equilibrium with each other is called boiling point.

For example, the boiling point of butane is -1.5 degree Celsius.

This means that at a temperature above -1.5 degree Celsius, butane will exist is gaseous state. That is, at a temperature of 24 degree Celsius butane will evaporate.

Thus, we can conclude that if we leave liquid butane in a bowl on a table in a room where the temperature is [tex]24^{o}C[/tex], butane will evaporate.

Answer:

Gravitational potential

Explanation:

Any object that is not on the surface of the Earth, but at a height instead has potential energy. Eventually, this can become kinetic energy once the object falls.

When an object is in a gravitational field, it has energy in its gravitational potential energy store.

12 × sin50 = 9.192533317........

Answer:

The brightness of a light depends on the amplitude of the light wave, which is the extent the waves moves from their equilibrium position. The brightness is also related to the amount of light that is emitted or reflected by an object

Therefore, compared to dim light, light that look bright have a higher amplitude and emit or reflect more light energy (photons)

Explanation:

Answer:

a) i) x = 0.25 m, ii) x = 0.10 m, iii)  x = 0.050 m

b) i)  x = 0.40 m

Explanation:

a) For this exercise we use the rotational equilibrium equation, where we assume that the anticlockwise rotations are positive.

1) L = 2W  

we set our reference system in the center of the bar where the fulcrum is

              ∑τ = 0

              W 0.50 - L x = 0

              x = 0.50 W / L

we substitute the value

              x = 0.50 W / 2W

              x = 0.25 m

ii) L = 5W

we calculate

              x = 0.50 W / 5W

              x = 0.10 m

iii) L = 10 W

               x = 0.50 W / 10W

              x = 0.050 m

b) a new weight is placed at x₂ = 30 cm on the left side

              W 0.50 + W 0.30 - L x = 0

              x = (0.50 + 0.30) W / L

              x = 0.80 W / L

we calculate

i)  L = 2W

                x = 0.80 w / 2w

                x = 0.40 m

Answer:

the positive and negative terminals of a battery are connected with a low resistance conductor.

Answer:

a is your answer.............

Answer:

(a) 37.5 kg

(b) 4

Explanation:

Force, F = 150 N

kinetic friction coefficient = 0.15

(a) acceleration, a = 2.53 m/s^2

According to the newton's second law

Net force = mass x acceleration

F - friction force = m a

150 - 0.15 x m g = m a

150 = m (2.53 + 0.15 x 9.8)

m = 37.5 kg

(b) As the block moves with the constant speed so the applied force becomes the friction force.

[tex]F = \mu m g \\\\150 = \mu\times 37.5\\\\\mu = 4[/tex]

The solubility of the sample will decrease

Answer:

1.261 billion

Explanation:The distance between the earth and the moon in miles is 250,000,so in feet,The distance is 1.261 billion

Answer:

A.

Explanation:

The pad extends the time so the impulse changes.

Answer:

A. The pad extends the time so the impulse changes

Explanation:

in term of physics it has same mass:)

Answer:

It is respected as leaders are accountable to the people. The rule of law within a democratic country will dictate what actions is considered wrong and punishable to do in that country. This will prevent people from harming and violating each other to get what they want and form a stable and safe society

Answer:

a) the other components are zero, in the direction of one of the coordinate axes

b) the magnitude is less than the value of one of its components, it must occur when the vector is in some arbitrary direction

9) constant velocity the acceleration must necessarily be zero,

constant speed  can be accelerated since it may be changing the direction of the velocity vector

Explanation:

Vectors are quantities that have modulo (scalar) direction and sense.

a)  If in a vector its magnitude is equal to one d its components implies that the other components are zero, therefore the vector must be in the direction of one of the coordinate axes

b) if the magnitude is less than the value of one of its components, it must occur when the vector is in some arbitrary direction, other than the direction of the axes, that is

          R² = x² + y²

where R is the magnitude of the vector e x, and are the components

9) When a particle has a constant velocity, the acceleration must necessarily be zero,

         v = vo + a t

The bold letters indicate vectors If a = 0 implies that v = vo

If a particle has constant speed it can be accelerated since it may be changing the direction of the velocity vector, this type of acceleration has the name of centripetal acceleration

Explanation:

The answer is Electrons move between objects.

At the ball's highest point, it has no vertical velocity, so the 6 m/s is purely horizontal. A projectile's horizontal velocity does not change, which means the ball was initially thrown with speed v such that

v cos(53°) = 6 m/s   ==>   v = (6 m/s) sec(53°) ≈ 9.97 m/s

The player shoots the ball from a height of 2.0 m, so that the ball's horizontal and vertical positions, respectively x and y, at time t are

x = (9.97 m/s) cos(53°) t = (6 m/s) t

y = 2.0 m + (9.97 m/s) sin(53°) t - 1/2 gt ²

Find the times t for which the ball reaches a height of 3.00 m:

3.00 m = 2.0 m + (9.97 m/s) sin(53°) t - 1/2 gt ²

==>   t ≈ 0.137 s   or   t ≈ 1.49 s

The second time is the one we care about, because it's the one for which the ball would be falling into the basket.

Now find the distance x traveled by the ball after this time:

x = (6 m/s) (1.49 s) ≈ 8.93 m

Answer:

2000g

Explanation:

volume=mass/density

=2000/2.5

=800cm³

mass=density×volume

=800×2.5

=2000g

Answer:

a. X: Slower in gases than liquids Y: Faster in solids than gases Z: Velocity depends on medium.

Explanation:

Speed of sound is fastest in solids. Sound waves travel more quickly in solid, than of liquid and gases. Sound waves travel most slowest in gases. Speed of sound varies significantly and it depends upon medium it is travelling through.  In more rigid medium sounds velocity will be faster.

Answer:

Explanation:

They traveled this distance in 2 parts, essentially. Part 1 had an average speed for a certain number of hours, part 2 had an average speed for a certain number of hours, and those 2 parts taken together took them a distance of 364 km. In equation form, that looks like this:

km/hr part 1 + km/hr part 2 = 364 km

Now we need to find each part on the left side of that equation. Part 1 first:

We traveled 65 km/hr for 2 hours, so that took us

[tex]65\frac{km}{hr}*2hr[/tex] and canceling out the hour label, we have that in part 1 we got

65(2) = 130 km. Good. Now onto the second part, where our unknown is.

We traveled 78 km/hr the second part for x hours, so that took us

[tex]78\frac{km}{hr}*xhr[/tex] and canceling out the hour label, we have that in part 2 we got

78x km. Now we can fill in the main equation (the one in bold print)

130 km + 78x km = 364 km and subtracting 130 km from both sides:

78x km = 234 km and dividing by 78 km:

x = 3 hours. Part 2 took 3 hours. Part 1 took 2 hours, so the whole trip took 5 hours.

Answer:

La ecuación para la velodiad del sonido en aire esta dada por:

[tex]v = \sqrt{ \frac{\gamma*R*T}{M} }[/tex]

Resolviendo esto para T, obtenemos:

[tex]T = v^2*(\frac{M}{\gamma*R} )[/tex]

donde:

T = temperatura del aire en grados Kelvin

γ = constante adiabatica = 1.4

R = constante del gas ideal =

M = masa molar del aire = 29*10^(-3) kg/mol

Si sabemos que el primer día la velocidad es 346 m/s, tenemos:

v = 346 m/s

Ahora podemos reemplazar todos esos valores en la ecuación para T, y asi obtener:

[tex]T = (346m/s)^2*(\frac{29*10^{-3}kg/mol}{1.4* 8.31 J/mol*K} ) = 298.42 K[/tex]

Para el segundo día la velocidad es 340 m/s, entonces ese día la temperatura va a ser:

[tex]T = (340m/s)^2*(\frac{29*10^{-3}kg/mol}{1.4* 8.31 J/mol*K} ) = 288.16 K[/tex]

Answer:

155mEq/L Cl-

Explanation:

A Ringer’s solution contains the following concentrations of cations: 146 mEq/L of Na+, 5 mEq/L of K+, and 4 mEq/L of Ca2+.

As Cl- is the only counterion of those cations:

For Na, the molecule is NaCl and the mEq/L of Cl- = mEq of Na+. The Cl- of the first ion is 146mEq/L Cl-

For K+, The molecule is KCl, mEq Cl- = 5mEq/L Cl-

And, for Ca2+, The molecule is CaCl2 but the equivalents of Ca2+ = Equivalents of Cl- = 4mEq/L Cl-

The total concentration of Cl- are:

146 + 5 + 4 =

Answer:

Explanation:

Use the kinematic equation.

This equation can be derived from [tex]f=ma[/tex], but we can just memorize, or look them up when needed as it saves us time.

Now we can plug our measurements into each variable to solve for acceleration.

Subtract 8m/s from both sides.

Divide by 5 seconds. Left with acceleration in terms of [tex]\frac{m}{s^2}[/tex]