4th SCI IA.1 Review

Match the type of simple machine to the object.

• jar lid

• inclined plane

• flagpole

• lever

• ramp

• wedge

• seesaw

• screw

• knife

• pulley

Which of these is an example of a compound machine?

• screw

• lever

• pulley

• scissors

Answer explanation

Scissors are a compound machine because they consist of two levers (the blades) that work together to cut. In contrast, a screw, lever, and pulley are all simple machines.

Jean is at the playground and goes down the slide. Which force is most responsible for bringing Jean down the slide?

• frictional force

• gravitational force

• applied force

• magnetic force

Answer explanation

The gravitational force is the primary force acting on Jean as she goes down the slide, pulling her downward due to Earth's gravity. While frictional force opposes her motion, it is the gravitational force that brings her down.

Tags

NGSS.MS-PS2-2

How does a pulley affect force?

• The pulley increases the force needed.

• The pulley changes the direction of the force.

• The pulley removes the need to use force.

• The pulley reduces the force needed.

Answer explanation

A pulley primarily changes the direction of the force applied, allowing you to lift objects more easily by pulling down instead of lifting up. This makes it easier to move heavy loads without increasing the force needed.

Which simple machine can be used to cut material?

• pulley

• wheel and axle

• inclined plane

• wedge

Answer explanation

The wedge is a simple machine specifically designed to cut or split materials. It works by converting force applied to its blunt end into a splitting force at its sharp edge, making it effective for cutting.

What type of simple machine is a seesaw?

• lever

• wedge

• screw

• pulley

Answer explanation

A seesaw is a type of lever, which consists of a rigid bar that pivots around a fulcrum. It allows for the lifting of one end when weight is applied to the other, demonstrating the principle of leverage.

Which simple machine is used to lift heavy objects with less effort?

• wedge

• inclined plane

• pulley

• screw

Answer explanation

A pulley is a simple machine that allows you to lift heavy objects with less effort by changing the direction of the force applied. It reduces the amount of force needed to lift the load, making it easier to move heavy items.

Adeline is doing an experiment. She pushes the same toy car down a shallow ramp onto 4 different surfaces. Which surface would it take the longest for the forces to become BALANCED?

• bath towel

• gravel driveway

• sandbox

• wooden floor

Answer explanation

The wooden floor provides less friction compared to the other surfaces, allowing the toy car to maintain its speed longer. This means it will take more time for the forces acting on the car to balance out on the wooden floor.

Tags

NGSS.3-PS2-1

NGSS.3-PS2-2

Which simple machine can be used to hold 2 objects together?

• inclined plane

• screw

• wedge

• scissors

Answer explanation

A screw is a simple machine that can hold two objects together by converting rotational motion into linear motion, effectively fastening them. Unlike the other options, it is specifically designed for this purpose.

Which of the following is NOT an example of a force?

• gravity

• magnetism

• screw

• pul

Answer explanation

A screw is a simple machine that converts rotational motion into linear motion, but it is not a force itself. In contrast, gravity and magnetism are fundamental forces that act on objects.