Physical Science

How does a double pulley system change the input force of a system?

• It halves the force required

• The force required is doubled

• It only changes direction

• It makes the force be with you.

Answer explanation

A double pulley halves the amount of force required by doubling the distance. It's the same amount of work and work = force x distance. So, if we increase the distance, we decrease the force.

Tags

NGSS.MS-PS2-1

NGSS.MS-PS2-2

When a pendulum swings, at which point is kinetic energy highest?

• 1

• 2

• 3

• 4

Tags

NGSS.MS-PS3-1

NGSS.MS-PS3-5

When a pendulum swings, at which point is potential energy at its greatest?

• 1

• 2

• 3

• 4

Tags

NGSS.MS-PS3-2

When a car burns gasoline it creates hot air to move the pistons in the engine, which causes the car to move. What energy transformation occur from the fuel to the movement of a car?

• thermal energy to mechanical energy

• thermal energy to chemical energy to mechanical energy

• chemical energy to thermal energy to mechanical energy

• chemical energy to electrical energy

Tags

NGSS.MS-PS3-5

Pressure is measured in what units

• Newtons

• m/s

• Pascals

• Moles

You build a simple machine to lift items into your tree house. The machine requires and input force of 25 N to lift the items with a weight of 125 N. What is the ideal mechanical advantage of the simple machine?

• 0.000258

• 100,215

• 5

• 0.20

Answer explanation

Ideal mechanical advantage equals output force/input force. The output force is just the weight of the items. The input force is stated.

Tags

NGSS.MS-PS2-1

NGSS.MS-PS2-2

What is the mechanical advantage of a ramp that is 8 m long and 2 m high?

• 16

• 0.25

• 85

• 4

Answer explanation

Mechanical advantage of a ramp is the lenght of the ramp divided by the height.

I apply 1,200 N of force to lift an object 20 meters. How much work did I do?

• 0 J

• 2400 J

• 600 J

• what is a J?

Answer explanation

A "J" is a Joule. It is the unit for work and is equal to 1N*m. To find work done, we multiply force times distance.

Tags

NGSS.MS-PS3-4

NGSS.MS-PS3-5

Mass and speed both affect the amount of kinetic energy an object has, but ____________ has a greater effect.

• mass

• speed

• volume

• weight

Tags

NGSS.MS-PS3-1

Where is kinetic energy the LEAST on a roller coaster?

• At the bottom of the first hill

• At the top of the first hill

• Halfway down the first hill

Tags

NGSS.MS-PS3-4

NGSS.MS-PS3-5