Which statement about van der waals forces is true? multiple
a. when the forces are weaker, a substance will have higher volatility.
b. when the forces are stronger, a substance will have lower viscosity.
c. when the forces are weaker, the boiling point of a substance will be higher.
d. when the forces are stronger, the melting point of a substance will be lower.

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.

The image shows a pendulum in simple harmonic motion the pendulum starts at a and swing to e

Aman throws a football straight into the air. as it rises, it slows down. which type of energy is the football gaining?