Amodel rocket blasts off and moves upward with an acceleration of 12 m/s2 until it reaches a height of 26 m. at that height, its engine shuts off, and it continues its flight in free fall. (a) what is the maximum height attained by the rocket? (b) what is the speed of the rocket just before it hits the ground? (c) what is the total duration (ins) of the rocket's flight?

Aroll in a paper machine is powered by a separately excited dc machine. operating point 1 (under load): the roll typically operates at 764 rpm and must provide 301 nm of torque to oppose the load of the paper. the armature voltage is 230v for this operating point operating point 2 (no load): when the load is removed the speed of the roll increases to 900 rpm (the field characteristics are unchanged) la ea dev m (a) calculate the maximum torque (units of nm) that the motor can supply with this applied voltage (b) calculate the value of the armature resistance, ra (in ohms) (c) at operating point 1 (loaded condition), the field current, i, and the total input power (armature field), are measured to be to be 10 a and 28,600 w respectively. use this information to calculate the value of the field resistance, rf (in ohms). (d) (d) at operating point 1 (loaded condition), calculate the motor efficiency. express your answer as a percent to at least 2 significant digits. (d) if the field voltage is reduced by 1/2, calculate the new stall torque (in nm) of the motor (f). if the field voltage is reduced by 1/2, calculate the new no-load speed (in rad/sec)

In a system, when potential energy decreases, then entropy also decreases. true false

If the chemical properties of a substance remain unchanged and appearance or shape of a substance changes it is called a ?