A train 90m long stops in a train station with its front buffers in line with a lamp post on the platform. Later it starts off with an average acceleration of 0.45m/s. What will be its speed in kilometers per hour when the tail buffers pass the lamp post P?​

Answer:

w = 0.01 t⁻²   rad/h

Explanation:

Let's use trigonometry to find the elevation angle of the telescope, we assume that the rocket remains fixed in the telescope.

        tan θ = CO / CA

the adjacent leg is CA = 16 km = 16 10³ m

Let's use kinematics to find the height of the rocket

          v = y / t

          y = v t

this height is equal to the opposite leg

          CO = v t

we substitute

         tan θ = vt / 16

         tan θ = 1200/16 t

         tan θ = 75 t

         θ = tan⁻¹ ( 75 t )

speed is defined by

          w = dθ/dt

          w = [tex]\frac{1}{1 + (75 t)^2} \ 75[/tex]  

as time increases we can neglect the 1 of the denominator

          w = 1/75 t²

          w = 0.0133 t⁻²

Using three significant figures

           w = 0.01 t⁻²   rad/h

for this answer the time must be given in hours

Answer:

TEJ as this is a thing you wont get

Answer:

Explanation: as,

v=f∧

v=200×10³×1.5×10³

v=2.7×10^7ms⁻¹

The velocity of the radio waves is 3 × 10⁸ ms⁻¹.

A radio station frequency = 200 KH

wavelength = 1.5 km

         Radio waves in the electromagnetic spectrum has the longest wavelength and it will always be below 300GHz. The radio waves can be generated with acceleration through some charged particles. Only through the transmitter via antenna the radio waves can gets transmitted. Radio waves can be used in all the electronic devices as mobile phones, radio communication, radars and navigations.

                               V = f λ

            Velocity,  v = ( 200 × 10³ ) × ( 1.5 × 10³ )

                               = ( 300 × 10⁶ )

                             v = 3 × 10⁸ ms⁻¹.

Hence, the velocity of the radio waves is 3 × 10⁸ ms⁻¹.

Learn more about the radio waves,

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Using first equation of kinematics

[tex]\boxed{\sf v=u+at}[/tex]

[tex]\\ \sf\longmapsto t=\dfrac{v-u}{a}[/tex]

[tex]\\ \sf\longmapsto t=\dfrac{30-6}{4}[/tex]

[tex]\\ \sf\longmapsto t=\dfrac{24}{4}[/tex]

[tex]\\ \sf\longmapsto t=6s[/tex]

Using 3rd equation of kinematics

[tex]\boxed{\Large{\sf v^2-u^2=2as}}[/tex]

[tex]\\ \Large\sf\longmapsto v^2=u^2+2as[/tex]

[tex]\\ \Large\sf\longmapsto v^2=24^2+2(4)(96)[/tex]

[tex]\\ \Large\sf\longmapsto v^2=576+768[/tex]

[tex]\\ \Large\sf\longmapsto v^2=1344[/tex]

[tex]\\ \Large\sf\longmapsto v=\sqrt{1344}[/tex]

[tex]\\ \Large\sf\longmapsto v=36.6m/s[/tex]

Answer:

Momentum = 100 Kgm/s

Explanation:

Given the following data;

Speed = 72 km/h

Mass = 5 kg

To find the momentum of the stone;

First of all, we would have to convert the value of speed to meter per seconds.

Conversion:

72 km/h to m/s = (72 * 1000)/3600 = 20 m/s

Momentum can be defined as the multiplication (product) of the mass possessed by an object and its velocity. Momentum is considered to be a vector quantity because it has both magnitude and direction.

Mathematically, momentum is given by the formula;

Momentum = mass * velocity

Substituting the values into the formula, we have;

Momentum = 5 * 20

Momentum = 100 Kgm/s

Answer:

1) Motion of air mass moving from equator northward (closer to earth axis)

2) Motion of object in orbit

3) Collision of 2 objects

4) Skater changing rotation by extension of arms

5) Motion of rocket due to velocity of expelled gas

Answer:

I THINK IT'S D....

HOPE SO

Answer:

Explanation:

The main equation to solve this is F = ma, where F is the force applied to the brakes with respect to its acceleration. We have the mass that we need, but we do not have the acceleration. That's the first thing we have to find. However, our velocity needs to be stated in m/s and right now it's in km/h. Converting that:

[tex]90\frac{km}{hr}*\frac{1000m}{1km}*\frac{1hr}{3600s} =25\frac{m}{s}[/tex] Now we're ready to find the acceleration:

[tex]a=\frac{v_f-v_0}{t}[/tex] where the top line there translates to the final velocity minus the initial velocity.

[tex]a=\frac{0-25}{3.0}[/tex] so the acceleration is -8.3 m/s/s

We can use that now in the force equation above:

F = 1200(-8.3) and

F = -1.0 × 10⁴ N (that's 10,000 N to the correct number of sig dig's; the negative sign means that the force is being applied in the direction opposite to that which the van is currently moving)

Answer:

Explanation:

By being close to an atom that will gladly take the electrons being offered.

Suppose you are talking about Be. It is in the second column. It has two outer electrons that can be given away. It will not give away one of the two remaining electrons because they are too close to the + nucleus.

Along comes a Fluorine atom. It has 7 electrons in its outer ring. The chemistry of the situation allows it to take on one of the two electrons Be is offering. It is all a matter of charges and attractions.

Another Fluorine atom will take on the remaining electron from the Be. The outer ring cannot take on more than 1 electron, but that is enough

Answer:

resistances is inversely proportional to the area of cross section of the conductor

Explanation:

The resistance of a wire is directly proportional to its length and inversely proportional to its cross-sectional area.

hope this helps you

have a nice day:)

Answer:It has 8550 j energy

Explanation:

(b) A uniform beam 150cm long weighs 3.5kg and

supported on knife-edges at its ends. The beam

supports a weight 7kg at a distance 30cm from

one end. Find the reactions of the supports.