Terms to Know
Solving
100

What is the apparent weight?

The normal force exerted on an object that is accelerating, often shown on a spring scale.

100

A 21 kg block of wood is hanging from a 32.9 kg block of wood.  Someone pulls up the system with a force of 484.2 N.  What is the acceleration of the system?

-.827 m/s2
200
What is the mass and friction of the strings in an ideal system?

Zero

200

What is the apparent weight of Holly (2425 kg), if she is in a rocket ship that is accelerating 21.3 m/s upward?

75,445 Newtons

300

What is the normal force?

The force of a surface on an object


Is perpendicular to the surface

300
A 12.1 kg desk is sitting in the middle of the classroom.  The coefficient of static friction is .91.  The coefficient of kinetic friction is .73.  If I was apply a force of 115 N, could I move the desk?


If so, how fast would the desk be accelerating?

Yes, because the Fsf max is 108 N (smaller than the applied force.


A = 2.34 m/s2

400

What is the tension force in a system?

the forces applied by a string on a system

400

A 848 kg box of sedated orangutans is sitting on a 76o incline.  If the coefficient of static friction is .2 and the coefficient of kinetic friction is .05, what is the smallest amount of force needed to start pushing the box up the incline?

If no external forces were applied to the system, how fast would the crate accelerate down the incline?

Fsf max = 402 N


a = 9.399 m/s2

500

What is the relationship between frictional forces and normal forces?

They are proportional to each other

500
A 12.1 kg block is resting on a table.  Over the edge of the table, a 21.3 kg block is connected by an ideal pulley.  If the coefficient of kinetic friction between the table and the block is .53, what is the acceleration of the system?


What is the tension force between the blocks?

a = 5.25 m/s2


F = 97.128 Newtons

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