A 23 kg mass is connected to a nail on a frictionless table by a ...

[olgavictoria]

A 23 kg mass is connected to a nail on a frictionless table by a massless string 1.3 m long. There is no appreciable friction between the nail and the string.
 
  If the tension in the string is 51 N while the mass moves in a uniform circle on the table, how long does it take for the mass to make one complete revolution?
  A) 5.2 s B) 4.8 s C) 3.8 s D) 4.5 s

Question 2

When a - particle is emitted from an unstable nucleus, the atomic number of the nucleus
 
  A) increases by 1.
  B) decreases by 1.
  C) increases by 2.
  D) decreases by 2.
  E) does not change.

[fauacakatahaias]

Answer to Question 1

B

Answer to Question 2

A

[olgavictoria]

Gracias!

[AmberC1996]

TYSM