Sketch the following speed-time graphs:
determine the:
- acceleration of the objects
- distance travelled
1. a car travels at a steady(constant) speed of 65 km/h for 3 hours.
2. a boy runs from rest and steadily accelerates to a speed of 10 m/s within 5 seconds.
3. a motorcycle accelerates steadily from 12 m/s to 24 m/s over a period of 6 seconds.
4. car decelerates steadily from a speed of 54 km/h until it stops 6 seconds later.

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.

What is the primary force that suspension bridges use cables to hold their spans up? a. tension force b. resistance force c. normal force d. elastic force e. applied force

Which is the correct symbol for an isotope of iodine with 53 protons and 78 neutrons?