All categories

3 years ago

A train travels at 270 km in 3 hours . what is the speed of the train?

Physics

2 answers:

yKpoI14uk [10]3 years ago

7 0

Rate times time = distance.

Rate = x
Time = 3 hours
Distance =270 km

Ann [662]3 years ago

3 0

$270 \div 3 = 90km / h$

You might be interested in

Charge q is 1 unit of distance away from the source charge S. Charge p is two times further away. The force exerted between S an

insens350 [35]

Answer : The correct option is, (d) 4 times

Solution :

According to the Coulomb's law, the electrostatic force of attraction or repulsion between two charges is directly proportional to the product of the charges and is inversely proportional to the square of the distance between the the charges.

Formula used :

$F=k_e\frac{q_1q_2}{r^2}$

where,

F = electrostatic force of attraction or repulsion

$k_e$ = Coulomb's constant

$q_1$ and $q_2$ are the charges

r = distance between two charges

First we have to calculate the force exerted between S and q when the distance between the charge is 1 unit and let us assumed that the charge be 'q'

$F_{sq}=k_e\frac{qq}{1^2}=k_e\times q^2$ ..........(1)

Now we have to calculate the force exerted between S and p when the distance between the charge is 2 unit at the same charge.

$F_{sp}=k_e\frac{qq}{2^2}=k_e\frac{q^2}{4}$ ...........(2)

Equation equation 1 and 2, we get

$\frac{F_{sq}}{F_{sp}}=\frac{1}{4}$

$F_{sq}=4\times F_{sp}$

Therefore, the force exerted between S and q is 4 times the force exerted between S and p.

5 0

3 years ago

Read 2 more answers

A ball on the end of a string is whirled around in a horizontal circle of radius 0.478 m. The plane of the circle is 1.02 m abov

m_a_m_a [10]

Answer:

Explanation:

We shall find first the velocity of ball at the time when string breaks. Let it be v . During its fall on the ground , 1.02 m below, we use the formula

h = 1/2 gt² where t is time of fall .

1.02 = 1/2 x 9.8 x t²

t²= .2081

t = .456

During this time it travels horizontally at distance of 2.5 m with uniform velocity of v

v x .456 = 2.5

v = 5.48 m /s

centripetal acceleration

= v² / r where r is radius of the circular path

= 5.48² / .478

= 62.82 m /s²

3 0

3 years ago

What would happen if all the powers of government were held by one person or one group of people? Would it be a good thing or a

EastWind [94]

Answer:

it would be a bad thing because if one person controlled the government then there would only be one mind in charge.

Explanation:

8 0

3 years ago

Neon atoms at 245 K pass through a fan that gives each mole of neon gas an additional kinetic energy of 16.0 J. Part A What is t

hjlf

Answer:

246.28 K

Explanation:

The total energy of one mole of gas molecules can be calculated by the formula given below

E = $\frac{3}{2}\times R\times T$

Where R is gas constant and T is absolute temperature.

Put the value of R as 8.314 and temperature as 245 , we get

E = $\frac{3}{2}\times 8.314\times 245$

= 3055.4 J

Add 16 j to it

Total energy of gas molecules = 3055.4 + 16 = 3071.4 J.

If T be the temperature after addition of energy then

$\frac{3}{2}\times 8.314\times T$ = 3071.4

T = $\frac{2\times 3071.4}{3\times 8.314}$

T = 246.28 K

7 0

3 years ago

Describe an object’s motion when balanced forces act on it

Alinara [238K]

Balanced forces do not cause a change in motion. When balanced forces act on an object at rest, the object will not move. If you push against a wall, the wall pushes back with an equal

3 0

3 years ago

Read 2 more answers