Level 4 Video #3: Brainpop - Balanced and Unbalanced Forces

How can we tell if an object is being acted upon by a force?

• The object is changing speed and/or direction.

• The object is moving at a constant speed.

• The object is sitting still.

True or false:

Force is a push or pull between at least two objects.

• True

• False

What is magnitude?

• Two forces 

• The size of the force

• The direction of the force

Why isn't Tim moving although Moby is pushing on him?

• Tim is pushing back more than Moby is pushing forward, so the forces are unbalanced toward their backs.

• Moby is pushing Tim more than Tim is leaning back, so the forces are unbalanced toward their fonts.

• Tim is pushing back just as much as Moby is pushing forward, so the forces are balanced.

What is  the unit of measurement for the strength of a force?

• Newtons

• Feet

• Liters

What is an unbalanced force?

• Unbalanced forces are when the two forces are equal, but opposite.

• Unbalanced forces are where a push or pull is stronger in one direction. 

When the plane is moving in a straight line at a constant speed, Tim says the net forces are zero. So, are the forces on the plane balanced or unbalanced?

• Balanced forces

• Unbalanced forces

If an object is slowing down, speeding up, or turning, is it being acted upon by  balanced or unbalanced forces?

• Balanced forces

• Unbalanced forces

Gravity, magnatism, and electrical forces act on things from a distance, so they are...

• contact forces.

• non-contact forces.

Tim & Moby  moved upward suddenly because

•  they jumped out of the plane causing a sudden increase in drag 

• they opened their parachutes causing a sudden increase in drag 

• they forgot to open their parachutes

• gravity no longer exists