Force

What is the unit for Force?

• Newtons (N)

• Kilograms (kg)

• Metres per second-squared (m/s²)

• newtons (n)

True or False: Force is a Vector

(careful with the randomised answer options!)

• TRUE

• FALSE

Answer explanation

Forces are described with a magnitude (number) AND a direction, so they are a vector quantity.

Which of these things does an resultant force NOT change in an object?

• Its speed

• Its shape

• Its direction of movement

• Its position

Answer explanation

A force acting on an object can change its speed, its direction of movement, and/or its shape.

The position of an object changes because it has a velocity, not necessarily because there is a force acting on it.

For example, walking at a constant speed means you are changing your position, but the resultant force acting on you is zero.

The force that attracts an object with mass to another object with mass (like yourself to the Earth) is called...

Answer explanation

The force due to gravity is called Weight.

Gravitational force is also acceptable.

GRAVITY is not!

Tags

NGSS.MS-PS2-4

What is the proper name for the total force acting on an object?

• The Resultant Force

• The Reaction Force

• The Overall Force

• The Combined Force

Answer explanation

The total/net force acting on an object is called the RESULTANT force.

Tags

NGSS.MS-PS2-2

A girl is skiing down a slope. During part of the run she remains at a constant speed while turning a corner.

Is there an unbalanced resultant force acting on her?

• Yes

• No

Answer explanation

Unbalanced forces can change speed, shape and direction of movement.

Even though her speed is constant, she is changing direction, so there must be an unbalanced resultant force acting on her!

Tags

NGSS.HS-PS2-1

What is the name of the force that all solid objects exert when in contact with another object?

For example, the force that stops your Chromebook falling through the desk.

Tags

NGSS.MS-PS2-1

If the resultant force on an object is zero (forces are balanced) what could be happening to an object?

Select all answers that apply.

• It remains at a constant speed in a straight line.

• It remains at a constant speed while turning.

• It is not moving.

• It is accelerating.

Answer explanation

An unbalanced force changes the velocity of an object (speed and/or direction!)

Therefore, when forces are balanced, an object will not change its velocity, so it doesn't move, or if it's already moving it will keep moving at the same speed and direction.

Tags

NGSS.MS-PS2-2

What is the resultant force on this object?

• 3N to the left

• 3N to the right

• 13N to the left

• 13N to the right

Answer explanation

8N (left) - 5N (right) = 3N to the left

Tags

NGSS.MS-PS2-2

What is the resultant force on this object?

• 0N

• 40N to the right

• 60N upwards

• 100N in all directions

Tags

NGSS.MS-PS2-2