a train covers half of its journey with a speed of 20 metre per second and the other of with the speed of 30 metre per second the average speed of the pain during the whole journey is

In the first law of thermodynamics, triangle e=q-w, what does q stand for

If a rock is thrown upward on the planet mars with a velocity of 12 m/s, its height (in meters) after t seconds is given by h = 12t − 1.86t2. (a) find the velocity of the rock after two seconds. m/s (b) find the velocity of the rock when t = a. 12−3.72a m/s (c) when will the rock hit the surface? (round your answer to one decimal place.) t = s (d) with what velocity will the rock hit the surface? m/s

Write a full page that sumerizes thermodynamics it’s from the website visionlearnig