Transcript CH11 Review Questions

Speed and Acceleration Graphs
CHAPTER 10
CH10 Question 1
Describe the object’s motion in the
graph above.
 Move a at constant speed for 4
sec, slows down for 3 seconds
then speeds up but not to original
velocity.
CH10 Question 2
Describe the object’s motion in the
graph above.
 Move a at constant speed for 4 s,
and comes to a rest.
CH10 Question 3
Describe the object’s motion in the
graph above.
 Positive acceleration for 5 seconds
– speeds up.
CH10 Question 4
Describe the object’s motion in the graph above.
 Constant speed 150s, const +accl.
For 100 s. Constant speed again
for 50 sec, then – accl for one sec.
CH10 Question 4
Calculate the object’s acceleration from 150 to 250
seconds.
 Vf-Vi/t = 30-10/100= 0,2 m/s2
CH10 Question 4
Calculate the object’s acceleration from 300 to 350
seconds.
 Vf-Vi/t = 5m/s-30m/s/50 s= -0.5 m/s2
Forces and Motion
CHAPTER 11
Question 1
State Newton’s First Law of motion
 An object at rest will remain at
rest and object in motion remain
in motion unless acted on by a net
force.
Question 2
State Newton’s Second Law of
Motion
 An object will accelerate in the
direction of a net force.
Question 3
State Newton’s Third Law of
Motion
 For every action there is an equal
and opposite reaction.
Question 1
What is the equation for calculating
Force when you know an object’s
mass and acceleration?
Question 1
What is the equation for calculating
Force when you know an object’s
mass and acceleration?
 Force = mass x acceleration
 F = ma.
Question 2
What are the units for Force?
Question 2
What are the units for Force?
 Kg  m/s2
 N = Newton
Question 3
A sailboat with a mass of 1000 kg is
accelerating at a rate of 8 m/s2.
What is the force of the wind
acting on the sail?
 F= ma
 F = 1000 kg x 8 m/s2 = 8000 N
Question 1
What equation do you use to
calculate acceleration if you know
the force acting on the object and
its mass?
 F= ma
 A = F/m = F  m
Question 2
What are the units for acceleration?
 m/s2
 “meters per second squared”
Question 3
What is the acceleration of a
50Kg swimmer that pushes off
the side of the pool with a force
of 100N?
 a = F/m = 100 kgm/s2  50 kg
= 2 m/s2
Question 1
What is the formula used to
calculate mass when you know
the Force on an object and the
resulting acceleration?
 F = ma
 m = F/a = F  a
Question 2
A weight lifter accelerates the
barbell at a rate of 2.0 m/s2 with
an applied force 400N. What is
the mass of the barbell?
 m = F/a = 400 kg m/s2  5 m/s2
 = 80 kg
Question 3
What is the relationship between
mass and inertia??
 As the mass increases the
inertia of an object increases
and a greater force will be
required to accelerate the
object.
Question 1
What is the formula used to
calculate the weight of an object
on Earth?
 weight = mass x gravitational acceleration.
 Gravitational acceleration on earth = 9.8 m/s2
Question 2
What is the difference between
mass and weight?
 Mass is a measure of how much
matter an object contains.
 Weight is a measure of the force
of gravity acting on that mass.
Question 3
Calculate the weight of 10 kg of
gold sitting on your desk.
 weight = mass x ag
 ag =9.8 m/s2
 W = 10 kg x 9.8 m/s2 = 98 N
Question 1
 m1  m2 
F  G

2
 d

Name this equation and the
variables that compose it.
Question 1
 m1  m2 
F  G

2
 d

Name this equation and the variables that
compose it.





Universal Gravitation
F = force of gravity
G = gravitational constant
m = mass of the objects
D2 = distance between the objects
Question 2
 m1  m2 
F  G

2
 d

According to the equation what
happens to the gravitational force
between two objects when they get
farther apart?
Question 2
 m1  m2 
F  G

2
 d

According to the equation what
happens to the gravitational force
between two objects when they get
farther apart?
d2 increases and the force of
gravity gets smaller.
Question 3
 m1  m2 
F  G

2
 d

According to the equation why does
our sun have a gravitational force
strong enough to hold all the
planets in orbit even though some
are very far away.
Question 3
 m1  m2 
F  G

2
 d

According to the equation why does
our sun have a gravitational force
strong enough to hold all the
planets in orbit even though some
are very far away.
 The sun has a very large mass
so its gravitational force is large
and far reaching.
Question 1
What is the term used to describe an
object where the only force acting
on the object is gravity ?
 Free Fall
Question 2
This is the maximum velocity a falling
object will reach as the upward force
of air resistance equals the downward
force of gravity?
 Terminal velocity
Question 3
If an object at terminal velocity is
experiencing balanced forces, how can
the object still be falling?
 Balanced forces only mean that
the object is not
ACCELERATING, it still falls @
a constant velocity.
Question 1
A fluid includes which three states of
matter?
 Liquids, gases, and plasmas
Question 2
What is the formula used to
calculate pressure and what unit is
pressure reported in?
 P = mass  Area = N/m2 = Pa
 Usually kPa (kilo Pascals)
Question 3
What is the air pressure if 20 N is
exerted over an area of 10m2?
 P = mass/Area = 20N  10m2
 = 2 Pa
Question 1
According to Bernoulli’s Principal
what happens to the pressure of
a fluid as the velocity of the fluid
increases?
Question 1
According to Bernoulli’s Principal
what happens to the pressure of
a fluid as the velocity of the fluid
increases?
 The pressure decreases.
Question 2
What is the upward force exerted
on an object immersed in a
fluid?
 Buoyant force or buoyancy.
Question 3
Archimedes Principal states that
for an object to float the weight
of the object must be equal to or
less than .. . . ?
Question 3
Archimedes Principal states that
for an object to float the weight
of the object must be equal to or
less than .. . . ?
 the weight of the fluid displaced
by the object.
Question 1
What term is used to describe the
resistance of of a gas or liquid to
flow?
 Viscosity.
Question 2
Hydraulic devices can increase
the output force by increasing
the output area. Which principal
predicts this characteristic?
 Pascal’s Principal- the pressure
of a liquid in an enclosed
system is uniform throughout
the system.
Question 3
According to the Venturi effect,
what happens to the velocity of
a fluid when it is forced to flow
through a smaller area??
 The velocity of the fluid
increases..
Question 1
What is the term for any object
thrown or launched from Earth
under the influence of gravity?
 Projectile
Question 2
Describe the horizontal and
vertical forces acting on the
cannon ball.
Question 3
Which will hit the ground first, the
cannon ball dropped straight down
or the one launched sideways?
They both hit at the
same time – horizontal
motion is independent
of vertical free-fall.