Question

?

Answer 1

for i and ii

U = gravitational potential energy = mgh

substitute the given values and solve for the unknown. make sure to read the problem carefully to see which value is the unknown and which ones are the given

Answer 2

(330)(9.8)(18.4)

Answer 3

good, that's your grav potential energy for i)

Answer 4

59505.6

Answer 5

good (don't forget units)

Answer 6

J?

Answer 7

yes

Answer 8

okay now for ii the same formula right?

Answer 9

yes

Answer 10

mgh=(330)(100000)(h)

Answer 11

g is the gravitational constant not the gravitational potential energy

Answer 12

is it would just be the total right?

Answer 13

yes

Answer 14

so 100000=330*9.8*h

Answer 15

yes

Answer 16

30.92

Answer 17

good

for iii) you will simply add the kinetic + potential energy using the formulas U = mgh and K = (1/2)mv^2

Answer 18

okay so find mgh first aand then k=1/2 etc and then add it together

Answer 19

yes

Answer 20

what is the m in mgh

Answer 21

1.3?

Answer 22

mass.

Answer 23

yeah i meant which number is the mass

Answer 24

it's the same steal beam as before

Answer 25

because the height is present

Answer 26

oh .

Answer 27

64680

Answer 28

good, keep going

Answer 29

is v 1.3?

Answer 30

yes

Answer 31

278.85

Answer 32

good, now keep going

Answer 33

64958.85

Answer 34

good, that's your answer

Answer 35

m/s right?

Answer 36

it is asking for total mechanical energy, what are the units of energy?

Answer 37

J

Answer 38

good, so joules

for iv) simply find the potential energy at that height

Answer 39

it would be mgh right?

Answer 40

yes

Answer 41

129,360

Answer 42

good, and since the potential energy is equal to the final kinetic energy that's your answer

Answer 43

for v) simply set potential energy = kinetic energy and solve for v

Answer 44

so 129360=

Answer 45

= kinetic energy

then solve for v

Answer 46

is it the one we solved in part iii

Answer 47

same formula not same value

Answer 48

what's the formula for kinetic energy?

Answer 49

K = (1/2)mv^2

Answer 50

good, so set potential = kinetic and solve for v.

Answer 51

129360=(1/2)mv^2

Answer 52

v=28?

Answer 53

good, 28 m/s = your answer