Across-country skier can complete a 7.5km race in 45min. what is the skiers average speed?

What is relative velocity? in which condition is relative velocity known by adding the velocity of the first body and that of the second body

A30 kg weight lies on top of a massless piston of area a = 0.01 m2 the exterior air is at a (constant) p =1 atm and t = 27 c. the interior gas is 0.4 moles of (ideal) n2 and it has initial temperature 27.00 degrees c. 1. what is the initial pressure in the interior? a. 29.4 kpa b. 130.7 kpa c. 101.3 kpa the next three questions concern what happens when an amount of heat q is slowly added to the interior, raising the piston by 1 mm and raising the interior temperature to 27.40 c

The free body diagram shows a box being pulled to the left up a 25-degree incline. the magnitude of the normal force is