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
makvit [3.9K]
3 years ago
14

A train travels 98 kilometers in 1 hours, and then 78 kilometers in 3 hours. what is its average speed?

Physics
1 answer:
ozzi3 years ago
7 0

The average speed over the total four hour interval is

\dfrac{98\,\mathrm{km}+78\,\mathrm{km}}{4\,\mathrm h}=31\,\dfrac{\mathrm{km}}{\mathrm h}

You might be interested in
Un movil viaja a 40km/h y comienza a reducir su velocidad a partir del instante t=0. Al cabo de 6 segundo se detiene completamen
aleksklad [387]

Answer:

1,85 m / s²

Explanation:

De la pregunta anterior, se obtuvieron los siguientes datos:

Velocidad inicial (u) = 40 km / h

Hora inicial (t₁) = 0

Tiempo final (t₂) = 6 s

Velocidad final (v) = 0

Aceleración (a) =?

A continuación, convertiremos 40 km / ha m / s. Esto se puede obtener de la siguiente manera:

1 km / h = 0,2778 m / s

Por lo tanto,

40 km / h = 40 km / h × 0,2778 m / s / 1 km / h

40 km / h = 11,11 m / s

Por tanto, 40 km / h equivalen a 11,11 m / s.

Finalmente, determinaremos la aceleración del móvil durante el período en el que desaceleró. Esto se puede obtener de la siguiente manera:

Velocidad inicial (u) = 11,11 m / s

Hora inicial (t₁) = 0

Tiempo final (t₂) = 6 s

Velocidad final (v) = 0

Aceleración (a) =?

a = (v - u) / (t₂ - t₁)

a = (0 - 11,11) / (6 - 0)

a = - 11,11 / 6

a = –1,85 m / s²

Por tanto, la aceleración del móvil durante el período en el que se ralentizó es de –1,85 m / s²

6 0
3 years ago
A block is given an initial velocity of 8.0 m/s up a frictionless 28° inclined plane. (a) What is its velocity when it reaches t
kramer

Answer:

A.) 8 m/s

B.) 7.0 m

Explanation:

Given that a block is given an initial velocity of 8.0 m/s up a frictionless 28° inclined plane.

(a) What is its velocity when it reaches the top of the plane?

Since the plane is frictionless, the final velocity V will be the same as 8 m/s

The velocity will be 8 m/s as it reaches the top of the plane.

(b) How far horizontally does it land after it leaves the plane?

For frictionless plane,

a = gsinø

Acceleration a = 9.8sin28

Acceleration a = 4.6 m/s^2

Using the third equation of motion

V^2 = U^2 - 2as

Substitute the a and the U into the equation. Where V = 0

0 = 8^2 - 2 × 4.6 × S

9.2S = 64

S = 64/9.2

S = 6.956 m

S = 7.0 m

4 0
3 years ago
Why is it very difficult for astronomers to find objects like planets and asteroids?
mezya [45]
It is difficult for astronomers to find object like planets and asteroids because it takes a lot of time to verify the objects locations and what surrounds a certain object in order to prove and be precise of its location
3 0
3 years ago
If the area of an iron rod is 10 cm by 0.5 cm and length is 35 cm. Find the value of resistance, if 11x10^-8 ohm.m be the resist
malfutka [58]

Answer:

Resistance of the iron rod, R = 0.000077 ohms    

Explanation:

It is given that,

Area of iron rod, A=10\ cm\times 0.5\ cm=5\ cm^2 = 0.0005\ m^2

Length of the rod, L = 35 cm = 0.35 m

Resistivity of Iron, \rho=11\times 10^{-8}\ \Omega-m

We need to find the resistance of the iron rod. It is given by :

R=\rho\dfrac{L}{A}

R=11\times 10^{-8}\times \dfrac{0.35\ m}{0.0005\ m^2}

R=0.000077 \Omega

So, the resistance of the rod is 0.000077 ohms. Hence, this is the required solution.

6 0
3 years ago
As stars age and become larger they become ________ and ________
sleet_krkn [62]
They become old and explode.
5 0
3 years ago
Other questions:
  • A ball having a mass of 500 grams is dropped from a height of
    12·2 answers
  • Monochromatic light with a wavelength of 6.4 E -7 meter passes through two narrow slits, producing an interference pattern on a
    10·1 answer
  • A tennis ball with a speed of 11.3 m/s is moving perpendicular to a wall. after striking the wall, the ball rebounds in the oppo
    11·1 answer
  • Find the kinetic energy of a 0.1-kilogram toy truck moving at the speed of 1.1 meters per second.
    14·1 answer
  • What is calculated by speed of light/wavelength?
    15·1 answer
  • The charge per unit length on a long, straight filament is-92.0 μC/m. (a) Find the electric field 10.0 cm from the filament, whe
    10·1 answer
  • What is the velocity of a 50kg skater if her momentum is 225kg. m/s?
    5·2 answers
  • Missy's favorite ride at the Topsfield Fair is the rotor, which has a radius of 4.0 m. The ride
    5·1 answer
  • Complete the ray diagram and label incident ray, refracted ray, angle of incidence, and angle of refraction ​
    15·1 answer
  • A glass rod with yellow crosses on it touches a sheet of silk covered with negative signs on it. the sheet of silk is sticking t
    15·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!