1/19/11 Day 8TOPIC: Conservation of Momentum Lab

OBJECTIVE: I will calculate momentum before and after an elastic collision

STARTER: Copy the following Conservation of Momentum equation.

Momentum before = Momentum after

m1v1+ m2v2 = m1v1 + m2v2

Table I : Collision DataMass

Of

Target

Car

(kg)

Mass

Of

Rolling

Car

(kg)

Rolling car

Before collision

Rolling car after collision

Target car after collision

Photo

Gate

(s)

Speed

(m/s)

.01/s

Photo

Gate

(s)

Speed

(m/s)

.01/s

Photo

Gate

(s)

Speed

(m/s)

.01/s

.102(2) .102(2) .0116 .862 0 0 .0141 .709

.102(2) .084(1) .0099 1.01 0 0 .0140 .714

.102(2) .056(0) .0080 1.25 .0533 .188 .0146 .685

COPY THE FOLLOWING DATA ON TO THE BOTTOM 3 LINES ON YOUR LAB REPORT

Masses

Empty Car .056 Kg

Car + 1 .084Kg

Car + 2 .102Kg

Car + 3 .130Kg

Marble = .028Kg

Ben bought 8 notebooks for $24.50. Some of the notebooks were $2.50 each, and the others were $3.25 each. If x represents the number of least expensive notebooks, which equation can be used to find the number of least expensive notebooks purchased?

A.$5.75(8 − x) = $24.50

B. $2.50(x − 8) + $3.25x = $24.50

C. $2.50x + $3.25(8 − x) = $24.50

D. $2.50x + $3.25(x − 8) = $24.50

SolveLooking:

# of least expensive books

Given:

8 notebooks

24.50 total cost

2.50 Least expensive

3.25 Most expensive

X=least expensive

Relationship/solve:

Total cost = (#of least exp.)2.5 + (# of most exp.)3.25

(24.50) = (x)2.5 + (8-x)3.25