7/30/2019 Answer to ACTIVITY 2.3

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Activity_2.3_Quantifying Forces Fnet=0 REDG040213

ACTIVITY 2.3

Quantifying Forces (Fnet=0)

CN_____ Name ____________________________________ Section_______________ Date______________

INSTRUCTIONS:

Use the idea of balanced forces--- all forces to the right must have the same magnitude as those to the

left and all forces up must have the same magnitude as those directed downward. Remember: for an

object to stay in constant speed or state of rest, the net is should be zero.

Identify the forces acting on each object below and write the magnitude of each identified force.

1. Static 2. Sliding at constant speed 3. Falling at constant speed

4. Sliding at constant speed

10 25 9 06F =F F cos cos . NN gy g

10 25 4 23F =F F sin sin . Nf gx g

5. Sliding horizontally atconstant speed

5 25 4 53F =T T cos cos . Nf x

g N y

N g y

g

F =F +T

F =F -T

=F -Tsin

=10-5sin25

=7.89N

6. The hand is pushing at theangle of the finger (forward

and down) and the rock

moves at a constant

velocity.

5 37 3 99F =F F cos cos . Nf ax a

g y N

N g y

g

F +F =F

F =F +F

=F +F sin

=10+5sin37

=13.01N

a

a

a

T=10N

Fg=10N

FN=10N

Fg=10N

R=10N

Fg=10N

FN=9.06N

Fg=10N

Ff=4.23N

25o25oT=5N

Fg=10N

Ff=4.53N

FN=7.89N

37o

Fa=5NFg=10N

Ff=3.99N

FN=13.01N