Una barra caliente de cobre cuya masa es de 1.5 kg se introduce en 4 kg de agua elevando su temperatura de 18°C a 28°C. ¿Qué temperatura inicial tenía la barra de cobre?

Suppose that a comet that was seen in 563 a. d. by chinese astronomers was spotted again in year 1951. assume the time between observations is the period of the comet and take its eccentricity as 0.986. what are (a) the semimajor axis of the comet's orbit and (b) its greatest distance from the sun?

In a vernier instrument the main scale is in 1/2 mm divisions .vernier is made by redividing 19 such divisions into 20 equal parts. calculate the least count of the instrument.

A110-pound person pulls herself up 4.0 feet. this took her 2.5 seconds. how much power was developed? 0.13 hp 0.32 hp 2.0 hp 3.1 hp