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
Alona [7]
3 years ago
12

A train travels 90 kilometers in 4 hours, and then 82 kilometers in 1 hours. What is its average speed?

Physics
1 answer:
kvasek [131]3 years ago
5 0
Average speed = total distance / total time.

That's 172 km / 5 hr = 34.4 km//hr
You might be interested in
Explain how balanced and unbalanced forces effect an objects motion differently
Kazeer [188]
Balanced Forces acting on an object will not change the object's motion. Unbalanced Forces acting on an object will change the change the object's motion.
5 0
2 years ago
You are working as a summer intern for the Illinois Department of Natural Resources (DNR) and are assigned to some initial work
serious [3.7K]

Answer:

Check the explanation

Explanation:

1) Pressure acting on the plug = Patm + P

Pressure = Patm + rho*g*h (Here h = D2)

Pressure = 101325 + 1000*9.8*7

Pressure = 169925 Pa

so, Force = PA

Force = 169925*pi*0.0152

Force = 120.1 N

7 0
3 years ago
011 10.0 points
Ulleksa [173]

Answer:

2.47 m

Explanation:

Let's calculate first the time it takes for the ball to cover the horizontal distance that separates the starting point from the crossbar of d = 52 m.

The horizontal velocity of the ball is constant:

v_x = v cos \theta = (25)(cos 35.9^{\circ})=20.3 m/s

and the time taken to cover the horizontal distance d is

t=\frac{d}{v_x}=\frac{52}{20.3}=2.56 s

So this is the time the ball takes to reach the horizontal position of the crossbar.

The vertical position of the ball at time t is given by

y=u_y t - \frac{1}{2}gt^2

where

u_y = v sin \theta =(25)(sin 35.9^{\circ})=14.7 m/s is the initial vertical velocity

g = 9.8 m/s^2 is the acceleration of gravity

And substituting t = 2.56 s, we find the vertical position of the ball when it is above the crossbar:

y=(14.7)(2.56) - \frac{1}{2}(9.8)(2.56)^2=5.52 m

The height of the crossbar is h = 3.05 m, so the ball passes

h' = 5.52- 3.05 = 2.47 m

above the crossbar.

8 0
3 years ago
Which statement best summarizes the central idea of “Applications of Newton’s Laws”?
Shkiper50 [21]

 

Newton's three forces, normal, tension and friction, are present in a surprising number of physical situations

Newton's Laws, that describe the relationship between an obejct and the forces acting upon it, apply in almost every physical situation, from quantum mechanics to electricity.

The correct answer is:

Newton’s laws can explain the forces that occur between objects every day


3 0
3 years ago
Read 2 more answers
A ray of light incident in water strikes the surface separating water from air making an angle of 10 ° with the normal to the su
labwork [276]

Answer:

a

 \theta _2  = 13^o

b

 \theta _1  =32.94^o

c

 \theta_c  =  53.05^o    

Explanation:

From the question we are told that

    The angle of incidence is  \theta_1 =  10^o

    The refractive index of water is  n_1 = 1.3

  Generally Snell's law is mathematically represented as

          n_1 sin(\theta_1) =  n_2 sin(\theta_ 2)

Here n_2 is the refractive index of air with value  n_2 =  1

         \theta_2  is the angle of refraction

So  

        \theta _2  =  sin^{-1}[\frac{n_1 * sin(\theta _1)}{n_2} ]

=>     \theta _2  =  sin^{-1}[\frac{1.3 * sin(10)}{1} ]

=>     \theta _2  = 13^o

Given that the angle should not be greater than \theta _2 =45^o  then the angle of incidence will be

       \theta _1  =  sin^{-1}[\frac{n_2 * sin(\theta _2)}{n_1} ]

=>     \theta _1  =  sin^{-1}[\frac{1 * sin(45)}{1.3} ]

=>     \theta _1  =32.94^o

Generally for critical angle is mathematically represented as

        \theta_c  =  sin^{-1}[\frac{n_2}{n_1} ]

=>     \theta_c  =  sin^{-1}[\frac{1}{1.3} ]  

=>     \theta_c  =  53.05^o            

4 0
2 years ago
Other questions:
  • The momentum of an electron is 1.75 times larger than the value computed non-relativistically. What is the speed of the electron
    13·1 answer
  • What is the volume of a 72 g of copper if copper has a density of 9 g/cm3
    10·1 answer
  • An element
    14·1 answer
  • Planet, , galaxy, universe. What is missing in the ordered sequence of the cosmos? A. Sun, B. Earth, C. Nebulae, D. Solar system
    12·2 answers
  • What question was asked by Faraday that the narrator calls a leap
    10·2 answers
  • i need to know The Sun and Moon seem to move across the sky each day because of Earth's ____________________ on its axis. The Mo
    10·1 answer
  • A speedboat initially at rest accelerates at 4.0 m/s (squared) for 7.0 s. How far does the speedboat move in 7.0 s?
    6·1 answer
  • Write an expression to evaluate the relative error in g (given that g= 2h/t^2) in terms of h,Δh,t,Δt
    14·1 answer
  • A solenoid with 35 turns per centimeter carries a current I. An electron moves within the solenoid in a circle that has a radius
    9·1 answer
  • Fredrick did an investigation on mass and acceleration. He applied a force to a toy car and measured the distance it moved. He t
    9·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!