Chapter 4 Review Problems

1
Chapter 4 Review Problems

• Questions
• 1-13 for Honors
• 1-7 for CP

2
Question 1- Galileos ideas

• Galileo rolled a ball down a smooth ramp and
  observed its path

3
Question 1- Galileos ideas

• Galileo rolled a ball down a smooth ball and
  observed its path

Ball attempts to seek the same height. Instead it
keeps rolling? Inertia
4
Question 2- find the weight
Weight mass x gravity Fg 35 kg x 9.8m/s2 Fg
343 kg m/s2 Fg 343 N
5
Question 3 Weight on Jupiter
Weight mass x gravity Fg 40 kg x 30m/s2 Fg
1200 kg m/s2 Fg 1200 N
6
Question 4 Find the Mass
7
Question 4- description
If my weight on earth is 550N, what is my mass?
The Answer
Newton kilograms (gravity)
550 x(9.8)
550/9.8x
X56.12 kg
8
Question 5 Find the Mass
40 N
5 N
Net Force 40N 5 N Net Force 35 N toward Me
9
Question 5 The tuG of wAr proBleM
If I pull a rope with 40N and Mr. F and Mr. H
pull together with 5N in the opposite direction,
what is the net force? 5N
40N a.) there would
be a net force of 35N If you help Mr. F and Mr. H
and pull with an additional 35N, what is the net
force? What is this situation called? b.) the net
force will be 0N. The object is now not moving
and is known to be in equilibrium
10
Question 6 car

• Inertia- you werent moving, now the car is
  moving and your body resists this motion so you
  body feels like it being pushed back, but its
  really just staying where it was, car is
  accelerating due to force.
• Inertia- Both you and the car are moving the same
  speed, the car slows down and you respond later
  so your body (and head) move forward.
• Inertia- Your body is moving in a straight line
  at a constant speed. The tires grip the road and
  turn the car, but your body tends to keep moving
  straightwhich is now the side of the car. (Good
  for smooshing brothers and sisters in the back
  seat or on roller coasters)

11
Question 6
The key to all the parts is
Inertia!!!!
12
Question 7 dropping peanuts on a plane

• The peanuts and the plane have the same velocity.
  When you drop the peanut it maintains the same
  forward (horizontal) velocityso it lands
  directly below where it was dropped.

13
Pregunta Numero Siete
When I drop a peanut on an airplane, why doesnt
it fly back and hit the person behind me?
When dropping a peanut on a moving vehicle, the
peanut has the same force compared to the earth
as the airplane. So the peanut does not move
because it has a net force of zero compared to
the airplane.
Created by, Graham Turner, Nicole Bish Bishop
and Foosey Kevin Strickland
14
Question 8 Net Force on a block
10 N
NET FORCE 5N up
5 N
15
Question 8
A block is pulled with 10N up and 5N down
10N
The net force is 5 N in the upward direction
because you subtract 5 N down from 10 N up
5N
16
Question 9 3 vector Combo!!
NET FORCE
4 N
8 N
7 N
17
Question 9 3 vector Combo!!
NET FORCE a2b2c29 64 c273 c28.5 N c
8 N
3 N
18
Question 10 2 Ropes
Support Force
Large component Force greater tension
Small component force less tension
Fg
19
Question 11- 400 N Dangling by 4 ropes Problem.

• I weigh 400 N. If I am dangling by 4 ropes, what
  is the tension in each rope?
• The tension in each rope is 100N
• b. If the two ropes snap there will be 200N of
  tension in each rope.
• c. If a friend throws down another line for me,
  the tension in all three ropes is about 133 N

Period 7 version
20
Continued 11
d. If I start climbing the rope up to my friend
using the rope thrown to me and I grab my friends
hand at the top, the tension on my friends hand
is 200N.
Science is Sexy
Science is Sexy
21
Question 11 description

• If you weigh 400N and you are hanging by 4 ropes
  then each ropes tension is 100N.

If two ropes snap, then each has 200N.
If a friend throws a line, then each has 133N
If a friend lent you his arm, the tension on the
arm would be 200N
Period 3 version
22
Question 12- 3 vector combo
Net Force 7 N
10N
10N
6.5 N
3.5N
45?
45?
6N
6N
2.5
5N
3.5N
3) Find resultant of remaining horizontal and
vertical components
1) Find components of 5N resultant
2) Find Sum of Forces that are 180o apart