#1 All students must perform all of the work of the activity in their science journals even though you are working in your lab group.

#2 When you are sure of your answer, transfer the information onto individual mini whiteboards.

#3 The whiteboard work is to remain on the white board until it is approved.

The mad scientist, Hugo A-go-go has developed a way to disrupt the electrical service to Chicago.

The mass of the Eastbound (traveling to your right) CTA is 40,000 kg while the mass of the Westbound CTA is 30,000kg.

The Eastbound transit is traveling at 20 m/s and the Westbound transit is traveling at 25 m/s.

There are two separate, stationary cars also on the same track. They are 10,000 kg each.

What is the eastbound train’s momentum?

P = mvKnown Want

m = 40,000 kg P (momentum)v = 20 m/s

P = mvP = (40,000 kg )(20 m/s) P = 800,000 (kg)( m/s)

Draw a momentum vector diagram of the eastbound train. Place the tip of the arrow at (0, 0) coordinates.

N y

W E

S

x

800,000 (kg)( m/s)

What is the westbound train’s momentum?

P = mvKnown Want

m = 30,000 kg P (momentum)v = 25 m/s

P = mvP = (30,000 kg )(-25 m/s) P = -750,000 (kg)( m/s)

Add the momentum vector of the westbound train to your vector diagram.

y

x

800,000 (kgm/s) 750,000 (kgm/s)

What is the momentum of each of the stationary transits?

P = mvKnown Want

m = 10,000 kg P (momentum)

v = 0 m/s

P = mv

P = (10,000 kg )(0 m/s)

P = 0 (kg)( m/s)

The Eastbound train collides with one of the stationary transits. Draw a momentum vector diagram that represents the above scenario just before the collision.

y

x

800,000 (kgm/s)

The Eastbound train collides with one of the stationary transits. Draw a momentum vector diagram that represents the above scenario just after the collision.

y

800,000 (kg)( m/s)x

The Eastbound train collides with one of the stationary transits. Sticking together, they continue to roll along the track. What is their velocity after the collision?

Net Momentum before = Net Momentum after

Known Wantme = 40,000 kg P beforeve = 20 m/s v afterms = 10,000 kgvs = 0 m/s

Pnet = (mv)net

P = me ve + msvs

P = (40,000 kg )(20 m/s) + (10,000 kg )(0 m/s) P = 800,000 (kg)( m/s)

v = P/mv = 800,000 (kg)( m/s) / (40,000 kg ) + (10,000 kg )v = 16 m/s E

The Westbound train collides with one of the stationary transits. Sticking together, they continue to roll along the track. What is their velocity after the collision?

Net Momentum before = Net Momentum after

Known Want

mw = 30,000 kg P beforevw = 25m/s v afterms = 10,000 kgvs = 0 m/s

Pnet = (mv)net

P = mw vw + msvs

P = (30,000 kg )(-25 m/s) + (10,000 kg )(0 m/s) P = -750,000 (kg)( m/s)

v = P/m

v = -750,000 (kg)( m/s) / (30,000 kg ) + (10,000 kg )v = 18.75 m/s W

The Westbound train, after the initial impact with the stationary transit collides with the Eastbound train also after its initial impact with one of the stationary transits. Calculate the velocity after the crash between the two trains if they stuck together.

Net Momentum before = Net Momentum after

Known WantPw = 750,000 (kg)( m/s) Pnet beforePe = -800,000 (kg)( m/s) v after

Pnet = Pe- Pw

Pnet = 800,000 (kg)( m/s) - 750,000 (kg)( m/s) Pnet = 50,000 (kg)( m/s) v = P/mv = 50,000 (kg)( m/s) / (40,000 kg ) + (50,000 kg )v = .56 m/s E

The Battalac, which has a mass of 1500 kg is occupied by batfink, 50 kg, and Karate, 150kg and is traveling at 50 m/s when it is forced off the road anddown a 50 meter embankment.

Calculate the vertical velocity of the Battalacjust before it strikes the ground.

Known Want

mB = 1,500 kg v

vohB = 50 m/s

mb = 50 kg

mk = 150 kg

vf2 = vo

2 + 2a∆y

vf2 = 0 m/s + 2(-9.8 m/s2)(50m)

v = -31.3 m/s

Calculate the magnitude of the velocity of the Battalac at impact with the ground.

y

50 m/s

31.3 m/s x

a2 + b2 = c2

502 + 31.32 = 58.99 m/s

or

TAN -1= 31.3/50

= 32.05*

Vf = Vx/COS 32.05*

= -58.99 m/s

or

Vf = Vy/SIN 32.05*

= -58.98 m/s

Calculate the momentum of the Battalac at the moment of first impact with the ground.

Known Want

mB = 1,500 kg P

vfB = 58.99 m/s

mb = 50 kg

mk = 150 kg

P = mv

P = (1700 kg)(-58.99 m/s)

P = -100,283 (kg m/s)