All categories

3 years ago

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

Physics

1 answer:

Elena-2011 [213]3 years ago

7 0

Total distance = 76+54 = 130km
total time = 2+5 = 7hrs
Av. speed = 130/7 = 18.571km/hr = 18.6 km/h ( 3 sig fig)

You might be interested in

To Mr. H's disgust, a 450-g black crow is raiding the recently-filled bird feeder. As Mr. H runs out the back door with his broo

bagirrra123 [75]

Answer:

Actually it's 2.50 m/s, sorry

Explanation:

It is solved by using momentum conservation equation

combined mass of crow and feeder = 450+670=1120 gm

let the recoil speed of feeder be v m/s

Then applying momentum conservation we get;

1120×1.5 = 670×v

v= 2.50 m/s

the speed at which the feeder initially recoils backwards = 2.50 m/s

5 0

3 years ago

) A stone initially moving at 8.0 m/s on a level surface comes to rest due to friction after it travels 11 m. What is the coeffi

natali 33 [55]

Answer:

-0.3

Explanation:

F' = μmg ........... Equation 1

Where F' = Frictional force, μ = coefficient of kinetic friction, m = mass of the stone, g = acceleration due to gravity.

But,

F' = ma ............ Equation 2

Where a = acceleration of the stone.

Substitute equation 2 into equation 1

ma = μmg

dividing both side of the equation by m

a = μg

make μ the subject of the equation

μ = a/g............... Equation 3

From the equation of motion,

v² = u²+2as................. Equation 4

Where v and u are the final and the initial velocity respectively, s = distance.

Given: v = 0 m/s (to rest), u = 8.0 m/s, s = 11 m.

Substitute into equation 4

0² = 8² + 2×11×a

22a = -64

a = -64/22

a = -32/11 m/s² = -2.91 m/s²

substitute the values of a and g into equation 3

μ = -2.91/9.8

μ = -0.297

μ ≈ -0.3

4 0

3 years ago

What is one result of meiosis?

kogti [31]

Answer:

meiosis is a kind of cell division which occurs in special cells like gametes in which the daughter cells have half the numbers of chromosomes than the parent cells .

hence we can say that by this cell division 2 haploid cells are formed.

7 0

3 years ago

In Thomson experiment, why was the glowing beam repelled by a negatively charged plate

algol13

<span>In Thomson experiment, why was the glowing beam repelled by a negatively charged plate, because the glowing beam was negatively charged. The glowing beam particles were attracted to the positive plate.

</span><span>J.JThomson proved that the cathode rays produced a stream of negatively charged particles called electrons. </span>

6 0

3 years ago

Read 2 more answers

An FM radio station broadcasts at 9.23 × 107 Hz. Given that the radio waves travel at 3.00 × 108 m/s, what is the wavelength of

STALIN [3.7K]

Answer:

3.2m

Explanation:

Given parameters:

Frequency of the FM radio = 9.23 x 10⁷Hz

Velocity of the waves = 3 x 10⁸m/s

Unknown:

Wavelength of the wave = ?

Solution:

To solve for the wavelength of the wave, we need the velocity equation;

Velocity = frequency x wavelength.

Radio waves are all electromagnetic radiations produced by both electrical and magnetic fields perpendicularly oriented to one another.

Since the unknown is wavelength, we solve for it:

3 x 10⁸ = 9.23 x 10⁷ x wavelength

wavelength = $\frac{ 3 x 10^{8} }{9.23 x 10^{7} }$

wavelength = 3.2m

7 0

4 years ago