Lesson 1 Flashcards
Tension (T) - This is any pulling force that acts alongg any object that does not l lose its shape because of
the force. If you pull on a rope or tug on a chain
the force involved is tension
away trom the body and acts along the line that pulls the body. If we have an actor suspended
Wres for a dynamic fight scene
we have the cables keeping him safe as he performs his stunts. Th
is tension along all the cables-as shown in figure 7.3. The direction of the tension is along the cable
His easy to nd We see tension in a pulled string of a guitar
the cable attached to hanging brido
and the rubber bands holding the walis tingting together.
Figure 7.3 The tension acts along the cable supporting the actor.
Friction (F) - This contact force comes out only when there is a force to oppose. It acts parallelto the
surfaces in contactand depends on the kind of surface in contact. Some examples of friction are evident
in rubbing your hands
using a pencil to write
in a direction that is both opposite the applięd force and parallel to the surfaces that are touching
as
we can see in figure 7.4
where the force applied on the bed is blue while the frictional force is yellow.
You can see that the force is not straight but the frictional force is parallel to the floor.
Figure 7.4
Friction always acts opposite the force but
parallel to the touching surfaces.
Elastic force (F) - This is the force used to stretch or compress an elastic body. It is the product of
the elastic constant
k
The elastic constant
k
unit N/m
while the distance is measured in meter. It is always negative because of the way the force
220 Science for a Changing World Grade 7
Samsung Dual Camera
Shot with my Galaxy A04e
