An object with a mass m= 250 g is on a plane inclined at 30 degreesabove the horizontal and is attached by a string to a mass m = 150g. there is no friction and mass m hangs freely and isinitially at rest. when mass m has descended a distance h = 10 cm, its speed will be
(a) 35.0 cm/s
(b) 7.0 cm/s
(c) 140 cm/s
(d) 110cm/s
(e) 70.0 cm/s

Arod of some material 0.20 m long elongates 0.20 mm on heating from 21 to 120°c. determine the value of the linear coefficient of thermal expansion [in (degrees c)^-1] for this material.

What do you think car designers do if the damage caused by a crash test is too severe?

Air is contained in a variable-load piston-cylinder device equipped with a paddle wheel. initially, air is at 400 kpa and 17°c. the paddle wheel is now turned by an external electric motor until 75 kj/kg of work has been transferred to air. during this process, heat is transferred to maintain a constant air temperature while allowing the gas volume to triple. calculate the required amount of heat transfer in kj/kg.