Net Force
When two forces are acting in opposite directions on an object, we (add / subtract) the Newtons of force.
Subtract
This is the type of force that pulls us toward the Earth.
Gravity
An object is not moving. Are the forces on the object balanced or unbalanced?
Balanced
Two students push a ball in the SAME direction with 2N each. What is the net force?
4N
Melanny pushes on a box with 20N of force to the right. Jose pushes on a box with 20N to the left. What is the net force on the box?
0N
Opposite poles of a magnet (attract / repel) each other.
Attract! The positive end of a magnet is attracted to the negative one.
A car slows down when turning onto a street. Balanced or Unbalanced?
Unbalanced
Student A pushes on a desk with 10N of force. Student B pushes back in the opposite direction with 100N of force. What is the net force?
90N
If the net force is 50N, the forces are (balanced / unbalanced)
Unbalanced
Touching
Ms. Barber's chicken is running at a constant speed of 20mph. The chicken does not speed up or slow down. Balanced or unbalanced?
Balanced - no change in motion.
Ms. Garcia leans on the wall with 50N of force, but the wall can only hold 40N of force. What will happen to Ms. Garcia? What is the net force in this scenario?
10N, Ms. Garcia will fall through the wall :(
Jasmine pulls a shopping cart with 100N of force, but it hits a rock, pushing her back with 5N of force. What is the net force on the shopping cart?
95N
Gravity is an example of a (contact force / non-contact force)
Non-contact force - objects do not need to be touching the Earth to be affected by gravity
If the net force is 0N, the forces are (balanced / unbalanced)
Balanced
A bird sits on a post and gravity pulls it down with 9N of force. The post pushes up on the bird with 9N of force. What is the net force? Are the forces balanced?
0N, balanced. The bird will sit peacefully on the post.
Liz leans on a wall with 5N of force. She does not fall into the wall and the wall does not move. How much force is the wall pushing back on Liz?
5N - balanced force
A car is sitting still on a street. Name 2-3 forces that are acting on this car.
Normal forces, gravity, balanced forces, friction (tires grip on the street)
Ms. Donihoo is playing tug-o-war with her class. She pulls with 25N of force. The class pulls with 4N of force.
What is the Net Force? Are the forces balanced or unbalanced?
21N in Ms. Donihoo's direction
Unbalanced
A baseball player hits a baseball with 340N of force. The baseball hits the bat with 60N of force. What is the net force?
280N