first and second newton law

Read this passage from the text and answer the questions that follow.

Inertia

Inertia is the tendency of an object to resist a change in its motion. If an object is already at rest, inertia will keep it at rest. If the object is already moving, inertia will keep it moving. Think about what happens when you are riding in a car that stops suddenly. Your body moves forward on the seat. Why? The brakes stop the car but not your body, so your body keeps moving forward because of inertia. That’s why it’s important to always wear a seat belt.

Questions

1. What is inertia?

2. Describe how inertia affects motion.

What is inertia? Describe how inertia affects motion.

The inertia of an object depends on its mass. Objects with greater mass also have greater inertia. Think how hard it would be to push a big cardboard box full of books. Then think how easy it would be to push the box if it was empty. The full box is harder to move because it has greater mass and therefore greater inertia.

question

1. What is the relationship between mass and inertia?

Newton’s first law of motion states than an object’s motion will not change unless.......

• the net force acting on it is greater than zero.

• a force continues to be applied to the object.

• its inertia is stronger than the applied force.

• the object has no inertia.

Overcoming an object’s inertia always requires a(n)

• large mass.

• massive force.

• unbalanced force.

• two of the above

It is more difficult to start a 50-kg box sliding across the floor than a 5-kg box because the 50-kg box has greater ....

• size.

• inertia.

• volume.

• velocity.

Newton’s first law of motion is also called the law of __________.

An object at rest will stay at rest unless a(n) __________ force acts on it.

Objects with greater mass have __________ inertia.

Read this passage from the text and answer the questions that follow.

Acceleration and Weight

Newton’s second law of motion explains the weight of objects. Weight is a measure of the force of gravity pulling on an object of a given mass. It’s the force (F) in the acceleration equation that was introduced above:

a=Fm

question

1. define weight?

If an object has a mass of 50 kg, what is its weight? if the gravity force is 10kg/s

• 500 N

• 50N

• 5 N

• none of them is correct