1. A ball is dropped from a cliff. If it takes the ball 1.75 seconds to hit the ground below, how high up is the cliff? Show all work, including the equation and substitution with
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25pts the diagram shows the positions of the sun, moon and earth during spring tides, when the high tides are at their highest and low tides at their lowest. what is it about these positions that causes these high and low tides?

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.

Which best describes how fluids change as they travel through different portions of the convection currents? they change to solids at the outer portion of the convection currents. they change to solids at the inner portion of the convection currents. they become more dense at the outer portion of the convection currents. they become more dense at the inner portion of the convection currents