Slide1: 50 Newton is about equal to

1. 10 lbs2. 23 lbs3. 50 lbs4. 110 lbs5. 250 lbs

Slide 2What is a net force?

1. A force acting on an object2. All the forces acting downward3. The combination of all the forces4. When all the forces cancel out

Slide 3You throw a rock in space. What is required to keep the rock moving at a constant velocity?

1. A constant force while its moving2. A very small force once its moving3. nothing

Slide 4A book is resting on a table. Since the book is not moving

1. There is not a force acting on it2. The table is pushing up with a greater force

than gravity is pulling down with3. Gravity is pulling down with a greater force

than the table is pushing up with4. The net force on the book must be zero

1.Move at a constant velocity2.Continually change velocity3.Move for a while at a constant velocity and

then change velocity4.It depends on how big the frictional forces are

Slide 5A constant (and not zero) net force is applied to a person on rollerblades. The person will…

Slide 6There is a zero net force acting on a person on rollerblades. You could say

1. The person is not moving2. The person is moving at a constant velocity

(not zero)3. The person is accelerating4. Not enough information to tell

Slide 7A person on rollerblades is pushed with a constant force of 10 N and experiences an unknown

force of friction. If the person moves at a constant velocity of 2 m/s, you could say…

1. friction = 0 N2. friction = 5 N3. friction= 10 N4. friction = 20 N

Slide 8To change the velocity of an object, you need

1. forces2. unbalanced forces3. inertia4. nothing