JC Science_Physics - Forces

Define force

• push or pull force

• force of gravity

• something that changes or tries to change the motion of an object

What instrument is used to measure a force needed to move an object?

• Einstein meter

• Newton meter (also called spring balance)

• Boyle meter

• Watson meter

Define friction

• Slows things down

• Needs oil

• Force because of sandpaper

• Force that opposes motion

Give two advantages of friction

• Ability to walk

• See objects clearly

• Brakes to slow down an object when required

• Carry sound waves

Give two disadvantages of friction

• Heat up our hands

• Wears down engine parts

• Limits top speeds

• Turns objects grey

What is Hooke's Law?

• The extension of a spiral spring is directly proportional to the force applied.

• The rate of change of a body's momentum is proportional to the force and takes place in the direction of the force.

• To every action there is an equal but opposite reaction.

• The rate of change of velocity.

Methods of reducing friction?

• Use oil (lubrication)

• Streamlining used in car design to reduce air resistance

• Ball bearings between the axle and the wheel

• All of the above

Who discovered gravity?

• Alexander Graham Bell

• Leonardo Di Vinci

• Isaac Newton

• Rosalind Franklin

What instrument is used to measure the mass of an object?

• Barometer

• Weighing scales

• (Electronic / pan top) balance

• Pipette

If the mass of a book is 3 Kg. What does it weigh?

• 3 Kg

• 30 N

• 3 N

• 30 Kg