Force and Motion

when a surface becomes smoother, the force of friction acting on an object moving on that surface

• decreases

• increases

• will be doubled

What effect will a pair of unbalanced forces have on an object that is at rest (not moving)

• The forces will not cause the object to move

• The object will continue to be at rest

• The object will move

What is the speed of a bird flying 20 km in 2 hours

• 18 km/hr

• 10 km/hr

• 40 km/hr

• 10 mi/sec

If you have two bulls going toward each other head on and both have force of 64N is it

• Balanced

• unbalanced

Natalie, Andrew, and Zach work together to hold the door shut to keep out zombies. Natalie pushes with a force of 12 N, Andrew pushes with a force of 15 N, and Zach pushes with a force of 22 N. What is the net force of the door

• 5 N

• 49 N

• 19 N

Three girls are pulling on rope in tug of war there force are 38 N, 15 N, and 14 N. Three boys are pulling on other side. There force is 35 N, 20 N, and 5 N. Calculate the net force to see who wil win the tug of war

• 93 N to the left - girls

• 60 N to the right- boys

• 33 N to the left- the girls

Describe the motion for ostrich from 0-to 30 minutes it is just a straight line

• increased rate of speed

• constant rate of speed

• no motion, it stopped

Describe the motion for ostrich from 30-45 minutes the line is not straight.

• increased speed

• constant speed

• no motion it stopped

Describe the motion for ostrich from 45-to 60 minutes it is a straight line across from 45 to 60

• increased speed

• constant speed

• no motion, it stopped

The arrow is going up is

• Normal

• applied

• friction

• gravity