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
kondor19780726 [428]
3 years ago
7

A train travels 76 kilometers in 2 hours and then 54 kilometers in 5 hours .What is the average speed ?

Physics
1 answer:
gizmo_the_mogwai [7]3 years ago
7 0
V = d ÷ t --> bc d=vt
V = (76+54)÷(2+5) = 130÷7 = 18.57km/hr
You might be interested in
An astronaut is a short distance away from her space station without a tether rope. She has a large wrench. What should she do w
Hitman42 [59]

Answer: b. Throw it directly away from the space station.

Explanation:

According to <u>Newton's third law of motion</u>, <em>when two bodies interact between them, appear equal forces and opposite senses in each of them.</em>  

To understand it better:  

Each time a body or object exerts a force on a second body or object, it (the second body) will exert a force of equal magnitude but in the opposite direction on the first.  

So, if the astronaut throws the wrench away from the space station (in the opposite direction of the space station), according to Newton's third law, she will be automatically moving towards the station and be safe.

3 0
3 years ago
Two ropes have equal length and are stretched the same way. The speed of a pulse on rope 1 is 1.4 times the speed on rope 2. Par
kondor19780726 [428]

Answer:

m1/m2 = 0.51

Explanation:

First to all, let's gather the data. We know that both rods, have the same length. Now, the expression to use here is the following:

V = √F/u

This is the equation that describes the relation between speed of a pulse and a force exerted on it.

the value of "u" is:

u = m/L

Where m is the mass of the rod, and L the length.

Now, for the rod 1:

V1 = √F/u1 (1)

rod 2:

V2 = √F/u2 (2)

Now, let's express V1 in function of V2, because we know that V1 is 1.4 times the speed of rod 2, so, V1 = 1.4V2. Replacing in the equation (1) we have:

1.4V2 = √F/u1 (3)

Replacing (2) in (3):

1.4(√F/u2) = √F/u1 (4)

Now, let's solve the equation 4:

[1.4(√F/u2)]² = F/u1

1.96(F/u2) =F/u1

1.96F = F*u2/u1

1.96 = u2/u1 (5)

Now, replacing the expression of u into (5) we have the following:

1.96 = m2/L / m1/L

1.96 = m2/m1 (6)

But we need m1/m2 so:

1.96m1 = m2

m1/m2 = 1/1.96

m1/m2 = 0.51

5 0
3 years ago
A capacitor of capacitance C has charge Q and stored energy is U if the charge is increased to 2Q then energy will be A)4U B)2U
Lubov Fominskaja [6]

Answer:

2u

Explanation:

2u

W = Vq

q = CV

W = V.CV

W = CV²

W/C = V²

V = √(W/C)

√(W1/C1) = √(W2/C2)

√(u/c) = √(x/2c)

x = 2u

8 0
3 years ago
A trip is taken that passes through the following points in order
Inessa05 [86]

Answer:

B) - 5.0 m

Explanation:

B is located on a positive location, 15m from the starting point A. Hence, since E is located a positive distance 10m from A, the difference becomes 10 - 15 = - 5.0 m

5 0
3 years ago
1) A record is spinning at the rate of 25 rpm. If a ladybug is sitting 10 cm from the
Sladkaya [172]

<h2>distance = 523 cm</h2>

Explanation:

( a ) The rotational speed of the ladybug = 25 r.p.m = 25/60 r.p.s

= 5/12 rev/sec

( b ) The definition of frequency is the number of rotations per second .

Here the number of rotations per second is 5/12 . Thus frequency = 5/12 Hz

( c ) The tangential speed is v = angular velocity x radius of rotation

The angular velocity ω = 2π x n , where n is the number of rotations per second

Thus angular velocity = 2π x 5/12   = 5π/6 rad/sec

The linear velocity = angular velocity x distance from center of record

Thus tangential speed = 5π/6 x 10 = 25π/3 cm/sec

Angular displacement in 20 sec = ω x t = 5π/6 x 20 = 50π/3 rad

Linear displacement = angular displacement x distance from center of record

= 50π/3 x 10 = 500π/3 = 523 cm

8 0
3 years ago
Other questions:
  • If R = 12 cm, M = 310 g, and m = 40 g , find the speed of the block after it has descended 50 cm starting from rest. Solve the p
    6·1 answer
  • A 500N person stands 2.5m from a wall against which a horizontal beam is attached. The beam is 6m long and weighs 200N. A cable
    12·1 answer
  • What if the population of rabbits decrease, what would happen with foxes and owls?
    8·1 answer
  • How to use kinetic energy to calculate velocity
    14·1 answer
  • What happens when two forces act in the same direction?
    14·2 answers
  • Why might compound gear trains be better than two gears alone?
    6·1 answer
  • the equitorial diameter of the moon is 3476 kilometers. if a kilometer equals 0.6214 miles, what is the moon's diameter in miles
    11·1 answer
  • A type of wave that carries energy from one place to another, even through
    11·1 answer
  • If you increase the frequency of a sound wave four times, what will happen to its speed?
    7·1 answer
  • Rachel and Sarah are on a bus travelling at 5 mph past John who is standing on the sidewalk. Rachel then throws a ball
    8·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!