Most geologists believe that the dinosaurs became extinct 65 million years ago when a large comet or asteroid struck the earth. Suppose an asteroid with a diameter of 2.0 km and a mass of 1.5 x 10^13 kg hits the earth with an impact speed of 3.5 x 10^4 m/s. Required:
a. What is the earth's recoil speed after such a collision?
b. What percentage is this of the earth's speed around the sun?

Which of the following represents an upright image? a. -do b. +m c. -m d. +do

The force will determine the acceleration.

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.