Lean las siguientes afirmaciones. Colocar V ó F. UNIDAD ABREVIATURA EQUIVALENCIA

Múltiplos

Kilómetro km 1000m
Hectómetro hm 100m
Decámetro dam 10m
Metro m 1m

Submúltiplos

Decímetro dm 0,1m
Centímetro cm 0,01m
Milímetro mm 0,001m

a)
4,25dam15,5m 
b)
1.350m 12hm 
c)
3,9mm1,1km 

dam hmm

a) Las magnitudes son propiedades que caracterizan a los cuerpos o a los fenómenos
naturales, y que no pueden de ser medidas.
b) Un alumno compara el largo del aula con una cantidad fija de la misma magnitud. Y a la
magnitud le asigna un número y una unidad, se dice, que está midiendo.
c) Un tiempo de: 15 minutos, una longitud de: 2 metros y una masa de: 250 gramos son
magnitudes vectoriales.
d) Las magnitudes fundamentales son: longitud, peso, tiempo, intensidad de la corriente
eléctrica, temperatura, intensidad luminosa y cantidad de sustancia.

Abaseball is thrown a distance of 20 meters. what is its speed if it takes 0.5 seconds to cover the distance

Zeros that follow non-zeros numbers and are also to the right of a decimal point are significant

Search coils and credit cards. one practical way to measure magnetic field strength uses a small, closely wound coil called a search coil. the coil is initially held with its plane perpendicular to a magnetic field. the coil is then either quickly rotated a quarter-turn about a diameter or quickly pulled out of the field. (a) derive the equation relating the total charge q that flows through a search coil to the magnetic-field magnitude b. the search coil has n turns, each with area a, and the flux through the coil is decreased from its initial maximum value to zero in a time ∆t. the resistance of the coil is r, and the total charge is q = i∆t, where i is the average current induced by the change in flux. (b) in a credit card reader, the magnetic strip on the back of a credit card is rapidly “swiped” past a coil within the reader. explain, using the same ideas that underlie the operation of a search coil, how the reader can decode the information stored in the pattern of magnetization on the strip. (c) is it necessary that the credit card be “swiped” through the reader at exactly the right speed? why or why not?