Answer:

Explanation:
As the path is straight, so the speed is equivalent to velocity. Now. assuming that the acceleration and deceleration of the train are constant. So, change of velocity with respect to time for acceleration as well as deceleration is constant. Hence, the slope of the speed-time graph is constant for the time of acceleration as well as deceleration. The speed for the time from
to
is constant, so slope for this interval of time is zero. The speed-time graph is shown in the figure.
The total distance covered by the train during the entire journey is the area of the speed-time graph.
Area


As velocity is in
and time is in
so the unit of area is 
Hence, the total distance is
.
Answer:
We feel cold when tap or well water in winter because heat flows from hot body to cold body.
Explanation:
Our <em>body</em><em> </em><em>is</em><em> </em><em>in</em><em> </em><em>optimal</em><em> </em><em>status</em><em> </em><em>is</em><em> </em><em>a</em><em> </em><em>hot</em><em> </em><em>body</em><em> </em><em>and</em><em> </em><em>tap</em><em> </em><em>or</em><em> </em><em>we</em><em>ll</em><em> </em><em>water</em><em> </em><em>is</em><em> </em><em>a</em><em> </em><em>cold</em><em> </em><em>body</em><em>.</em><em> </em><em>Theref</em><em>ore</em><em> </em><em>we</em><em> </em><em>feel</em><em> </em><em>cold</em><em>.</em>
Answer:
Explanation:
Work done in lifting the weight once = mgh
= 20 x 9.8 x (1.9+1.7)
= 705.6 J
= 705.6 / 4.2 calorie
= 168 cals
Total energy to be spent = 600 x 10³ cals
No of times weight is required to be lifted
= 600 x 10³ / 168
= 3.57 x 10³ times
Total time to be taken = 2 x 3.57 x 10³
= 7.14 x 10³ s
=119 minutes .
Answer:
diameter = 21.81 ft
Explanation:
The gravitational force equation is:

Where:
- F => Gravitational force or force of attraction between two masses
- M => Mass of asteroid 1
- m => Mass of asteroid 2
- R => Distance between asteroids 1 and 2 (from center of gravity)
We also know that the asteroids are identical so their masses are identical:
Since R is the distance between centers of the two asteroids and their diameters are identical (see attachment), we can conclude that:
We don´t know the mass of the asteroids but we know they are composed of pure iron, so we can relate their masses to their density:
This is going to be helpful because the volume of a sphere is:
And know we can write our original force of gravity equation in terms of the radius of the asteroids:
Now let´s plug in the values we know:
mutual gravitational attraction force
gravitational constant
Solve for r and multiply by 2 because 2r = diameter
Result is d = 21.81 Feet