Catherine Ndereba is a pretty good halfmarathon runner. So much so, that she finds it too easy and is tired of filling her room with trophies and medals! In her last race she decided to tie a rock to her waist, to give the other runners a chance, and she still finished The rock had a mass of 4.0*10^ 1 kg and she ran at a constant velocity forwards while exerting an applied force of 155 N at 27 to the horizontalCatherine even had time during the race to determine the coefficient of kinetic friction between the rock and the ground. What was her answer? Draw a FBD.

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.

Why is it important always to use horizontal bars in unit fractions when performing unit conversions?

Consider a system with two masses that are moving away from each other. why will the kinetic energy differ if the frame of reference is a stationary observer or one of the masses?