Physics Class Monday Sub Day

Dimensional Analysis

Answer
Your European hairdresser wants to cut

your hair 8.0 cm shorter. How many
inches will he be cutting off?

8.0 cm

1 in
2.54 cm = 3.2 in

cm in

Practice Dimensional Analysis

Taft football needs 550 cm for a 1st down.

How many yards is this?

2.54 cm= 1 inch
12 inches=1 foot
3 feet = 1 yard

Dimensional Analysis

Answer:
Taft football needs 550 cm for a 1st down.

How many yards is this?

550 cm

1 in

2.54 cm

cm

yd

1 ft
12 in

1 yd
3 ft

​=6.0 yards

Practice Dimensional Analysis

A piece of wire is 1.3 m long. How many

1.5-cm pieces can be cut from this wire?

2.54 cm= 1 inch
12 inches=1 foot
3 feet = 1 yard

Practice Dimensional Analysis

Answer:
A piece of wire is 1.3 m long. How many

1.5-cm pieces can be cut from this wire?

1.3 m

100 cm

1 m
= 86 pieces

cm

pieces

1 piece
1.5 cm

New Topic: Scientific Notation

� Converting into Sci. Notation:

⬥ Move decimal until there’s 1 digit to its

left. Places moved = exponent.

⬥ Large # (>1) ⇒ positive exponent

Small # (<1) ⇒ negative exponent

⬥ Only include sig figs.

65,000 kg → 6.5 × 104 kg

I. Scientific Notation

7. 2,400,000 μg

8. 0.00256 kg

9.

7 × 10-5 km

10. 6.2 × 104 mm

Practice Problems

2.4 × 106 μg

2.56 × 10-3 kg

0.00007 km

62,000 mm