1st trial: The student decided to mix 250 mL of water at 20 degrees Celsius with 250 mL of water at 98 degrees C. After waiting some time, she recorded the temperature of the mix to be 56 degrees C. 2nd trial: The student decided to mix 200mL of water at 98 degrees C. After waiting some time, she recorded the temperature of the mix to be 72 degrees C. 3rd trial: The student decided to mix 300 mL of water at 15 degrees C with 150 mL of water at 90 degrees C. After waiting some time, she recorded the temperature of the mix to be 41 degrees C.

Achild throws a ball with an initial speed of 8.00 m/s at an angle of 40.0° above the horizontal. the ball leaves her hand 1.00 m above the ground. how long is the ball in flight before it hits the ground?

For problems 1-3, consider a simple dc brush motor with a permanent magnet stator. with an an consider a simple dc brush motor with a permanent magnet ae supply voltage of 100 v, the no-load speed of the motor is 1000 rpm. this motor can provide a torque of 1.9 n-m at 800 rpm drawing a current of 2 a current are both zero at no load.) 1. with an armature supply voltage of 100 v, the motor is operated at 900 rpm. what is the motor torque? what is the mechanical power delivered by the motor? what is the current draw? what is the electrical power input? what is the energy efficiency of the motor? with an armature supply voltage of 100 v, the motor is operated at 1100 rpm (where it acts as a generator). what torque input is required? what mechanical power is required what current is generated? what is the electrical power generated? what is the energy efficiency of the motor acting as a generator? 2. with an armature supply voltage raised to 120 v, the motor is operated at 1000 rpm. what is the no-load speed? what is the motor torque? what is the mechanical power delivered by the motor? what is the current draw? what is the electrical power input what is the energy efficiency of the motor? 3.

If an athlete runs once around a track, back to the starting line, her average velocity is zero. true or false?