PH 201 — Unit Challenge

Conversions

100

Convert:

120s→min 

2 min

200

350cm→m

3.50m

300

Convert 425 cm to meters. Show your conversion factor.

425cm((1m)/(100cm))=4.25m

400

Using  1 in=2.54 cm  

convert:  5.36in→cm 

approximately 13.6cm

500

Convert 425 cm to meters. Show your conversion factor.

425cm((1m)/(100cm))=4.25m

Cancel Those Units!

100

Which conversion factor should you use to convert seconds to minutes? 

A. (60 sec)/(1min)

B. (1min)/(60 sec)

B

200

Set up—but do not calculate—the conversion:

250cm→m 

250cm((100cm)/(1m))

300

Set up, but do not calculate:

Convert 7.50 km to meters.

7.50km((1000m)/(1km))

400

1mile=1609.34m       1hr=3600s

3.00×10^8 m/s→ (mil) / (hour)

3.00×10^8s/m((1mil)/(1609.34m))((3600s)/(1hr))

500

Set up the conversion from m/s to mi/h. Do no calculate

A speed is given in m/sm/s. Using:

1mile=1609.34m   and 1hr=3600s 

m/s((1mil)/(1609.34m))((3600s)/(1hr))

Unit Detective

100

Velocity: If dd is measured in meters and tt in seconds, what is the unit of velocity? 

v=(d/t)

m/s

200

Acceleration:

a= v/t

What is its SI unit?

m/s^2

300

If acceleration is change in velocity divided by time, what SI unit should acceleration have?

(m/s)/s=m/s^2

400

Starting with mass × acceleration, determine the fundamental SI units of force.

kg(m/s^2)=(kg⋅m)/s^2

500

Force: F=ma  Given: m=kg

a=m/s^2

kg⋅m/s^2=N

Equation Check

100

v=d/t

If v=m/s, d=m, and t=s:

👍 CONSISTENT

200

F=ma  Given: F=N,m=kg,

a=m/s^2

 

👍 CONSISTENT

300

For  F=m use the units of mass and acceleration to determine the units of force.

Mass= F=kg

A = m/s^2

 F=kg⋅m/s^2 = N 

400

A student says that the distance traveled by an object can be calculated using: d = vt^2

where:    d = distance   v = velocity   t = time

Use dimensional analysis to determine whether this equation can be correct.

❌ Not dimensionally consistent ❌

500

T=2πsqrt(L/g)

Given: L=m and

g=m/s^2

 

👍 CONSISTENT