Great question !
The rate at which an object covers distance, without worrying
about the direction it's moving, is the object's SPEED .
When the direction is also given, then you have the object's VELOCITY.
This question is important. It gives us a chance to point out that
"velocity" is not just a fancy word for speed that you use when you
want to sound smart. There's actually an important difference between
'speed' and 'velocity'.
8. In soft magnetic materials such as iron, what happens when an external magnetic field is removed?
a. The domain alignment persists.
b. The orientation of domains fluctuates.
c. The material becomes a hard magnetic material.
d. The orientation of domains changes, and the material returns to an unmagnetized state.
9. According to Lenz’s law, if the applied magnetic field changes,
a. the induced field attempts to keep the total field strength constant.
b. the induced field attempts to increase the total field strength.
c. the induced field attempts to decrease the total field strength.
d. the induced field attempts to oscillate about an equilibrium value.
10. The direction of the force on a current-carrying wire in an external magnetic field is
a. perpendicular to the current only.
b. perpendicular to the magnetic field only.
c. perpendicular to the current and to the magnetic field.
d. parallel to the current and to the magnetic field
Given,
Effort force = 120 N
Load force= 1050 N
Mechanical advantage of a pulley is given by the ratio of load force to the effort force.
Therefore, the mechanical advantage of the given pulley is 8.75.
Since the bulb consumes 100 watts of power and its efficiency is 95%,
it generates 95 watts of light energy and 5 watts of heat energy whenever
it's turned on.
5 watts means 5 joules of energy per second.
(2.5 hours) x (3,600 seconds/hour) = 9,000 seconds
(9,000 seconds) x (5 joules/second) = 45,000 joules of heat in 2.5 hours
