Unit 2

Question 1

Work=

Answer 1

Force * displacement
Joules, scalar

Question 2

If work is perpendicular, what does it equal to

Answer 2

Zero

Question 3

Kinetic energy?

Answer 3

KE = 0.5mv^2
Joules
Scalar

Question 4

What does work total equal?

Answer 4

Change in KE

Question 5

Conservative forces?

Answer 5

Spring, gravitational, electrostatic

Question 6

What does W =

Answer 6

Fscos€

Question 7

Power?

Answer 7

P=Force*velocity
Scalar
Rate at which W is done
Watt (J/s)
Average Power = change in W / change in time

Question 8

Ug =

Answer 8

mgy
!reference point!

Question 9

Mechanical energy =

Answer 9

E=U+K
Wtot=Ww=-change in Ug=-(mgy2-mgy1)

Question 10

When does Ei=Ef?

Answer 10

Constant energy and if conservative forces
K1+Ug1=K2+Ug2

Question 11

Spring F?

Answer 11

Fx=-kx
X=L-Lo

Question 12

Elastic PE?

Answer 12

Uel=.5kx^2

Question 13

What does Ws=?

Answer 13

-deltaUel

Question 14

Momentum=

Answer 14

mv
Ns
Vector

Question 15

Impulse=

Answer 15

P2-P1

Question 16

J=?

Answer 16

J=Fnet,avg=deltaP/deltaT

Question 17

J also =

Answer 17

J=FdeltaT=F(t2-t1)

Question 18

Summation of Force=

Answer 18

dP/dT

Question 19

Conservation of momentum?

Answer 19

Pi=Pf
Jnet=0, P conserved

Question 20

E initial and final with a non-conservative force?

Answer 20

Ei+Wnc=Ef
Non-conservative force < 0

Question 21

Khan equation?

Answer 21

J=deltaP=FndeltaT

Question 22

What is KE when you are completely inelastic?

Answer 22

DeltaKE<0
MOMENTUM CONSERVED

Question 23

Inelastic and elastic, KE and P?

Answer 23

Elastic, both conserved
Inelastic, KE not conserved, P conserved

Question 24

What is the impulse difference between a brick or a pillow stopping an object?

Answer 24

The impulse is the SAME

Question 25

t=

Answer 25

square root of 2y/g

Question 26

.5mvi^2 = uk*mgs

Answer 26

Yep

Question 27

What’s an alternative method to think of solving if you are having troubles

Answer 27

Think in what final units need to be

Question 28

(Pa+Pb)i=

Answer 28

(Pa+Pb)f

Question 29

Small car, large truck…
Impulse difference?
Average force difference?

Answer 29

No difference.
Receive the same impulse and experience the same average force

Question 30

Work energy theorem?

Answer 30

Wtot=deltaKE
If distance doubles, work will double, hence KE doubles