Unbalanced & Balanced Forces

A runner, jumping over a hurdle.

• Balanced Force

• Unbalanced Force

Answer explanation

Whenever position, direction, or speed changes - it is considered an unbalanced force.

It is unlikely the runner is running at a constant speed and when they jump into the air they are changing their direction.

Tags

NGSS.MS-PS2-1

NGSS.MS-PS2-2

A lamp sitting on a table.

• Balanced Force

• Unbalanced Force

Answer explanation

The speed, direction and position don't change - so it is considered balanced!

Tags

NGSS.3-PS2-1

A car accelerating around a mountain curve.

• Balanced Force

• Unbalanced Force

Answer explanation

Not only is it considered unbalanced because the car is turning - but also because the car is speeding up!

Tags

NGSS.MS-PS2-2

Two ice skaters moving in a straight line at a constant speed.

• Balanced Force

• Unbalanced Force

Answer explanation

Remember, it's considered a balanced force if they remain in a straight line (direction) and going the same (constant) speed.

A skier skiing through flags in a race down the mountain.

• Balanced Force

• Unbalanced Force

Answer explanation

The skier is accelerating down the mountain and turning!

Tags

NGSS.MS-PS2-1

NGSS.MS-PS2-2

A book sitting on a shelf.

• Balanced Force

• Unbalanced Force

Answer explanation

Remember there are two forces on an object that is not moving.

Gravitational Forces & Normal Forces!

Tags

NGSS.3-PS2-1

A gymnast on a balance beam doing a backflip.

• Balanced Force

• Unbalanced Force

Answer explanation

Even though she's balancing on a beam, she's an unbalanced force. She is changing her direction and speed!

Tags

NGSS.MS-PS2-4

NGSS.MS-PS3-1

NGSS.MS-PS3-5

Cars in a NASCAR race speeding around the track.

• Balanced Force

• Unbalanced Force

Answer explanation

Not only are the cars turning, but when racing cars accelerate (speed up) and decelerate (slow down) a lot!

Tags

NGSS.MS-PS2-1

NGSS.MS-PS2-2

NGSS.MS-PS3-1

NGSS.MS-PS3-5

A soccer ball sitting on the ground motionless.

• Balanced Forces

• Unbalanced Forces

Answer explanation

While the ball is sitting there it's considered balanced.

But once it's kicked - it's unbalanced!

A rocket lifting off the launch pad.

• Balanced Force

• Unbalanced Force

Answer explanation

Rocket's are able to lift off because of the thrust pushing out the bottom of the rocket!

Tags

NGSS.HS-PS2-1