Newton's 2nd Law

All forces are measured with the units of:

• kg

• m/s²

• N

• m/s

How are force and weight the same?

• Both are measured in kg

• Both are measured in m/s²

• Both are measured in N

• Both are measured in m/s

If I am trying to calculate the amount of force needed to accelerate an object, the formula I will use is:

• F=m*a

• m=F/a

• a=F/m

• S=D/T

A 1000 kg car is accelerating a 5 m/s², how much force is required?

• 1000 N

• 5 N

• 5000 N

• 5000 m/s²

What is the acceleration of a 0.15 kg baseball hit with a force of 16,000 N (that's not a typo!)

• 106,667 m/s^2

• 2,400 N

• 1 m/s^2

• Baseball's don't accelerate when hit.

An airplane has a mass of 41,000kg. At take off, it accelerates at 4 m/s². How much force is required?

• 164,000 N

• 164,000 m/s²

• 10,250 kg

• 10,250 F

To calculate weight, the formula you need is:

• W = mass*gravity

• mass = Weight/gravity

• gravity = weight/mass

• A bathroom scale

You are headed to Mars! If your mass is 60kg and the gravity on Mars is 3.72m/s², what will your weight on Mars be?

• 223.2 W

• 16 N

• 16 W

• 223.2 N

How are mass and weight different?

• They are the same thing!

• Mass is amount of matter, weight is gravity acting on mass

• Mass includes weight, but weight doesn't include mass

• There is always more mass than weight.

Why is it easier to push a heavy object than to lift a heavy object?

• Everything always has more friction than weight.

• Inertia > Weight

• Lifting means you fight gravity, pushing is fighting inertia.

• Because of momentum.