Newton's Laws - Mission NL9 Detailed Help

The cable of a freight elevator applies a 3000-N force to accelerate a 250-kg elevator upward. Fill in all blanks in the diagram below and determine the magnitude of the acceleration (in m/s/s) of the elevator. (Use the approximation that g ~ 10 N/kg.) ... 
 
(Note: Numbers are randomized numbers and likely different from the numbers listed here.)



 
The big idea in this problem is to determine the acceleration of the object from knowledge of all the individual forces. The following method will assist your solution to the problem.
 
  • One of the two individual forces (Ftens) is explicitly stated. The force of gravity can be determined from the object's mass (see Formula Fix section; use g = 10 N/kg).
  • The net force is the vector sum of all the forces. Since both forces are known, they may be added as vectors to determine the net force (see the link in Hot Link section if necessary).
  • The acceleration of the object is found using Newton's second law equation: a = Fnet/m. Since both Fnet and m are known, plug and chug and you have your acceleration value.


 
The mass of an object is mathematically related to its weight by the equation: 
 
Weight = Fgrav = mass • g

where g is the gravitational field strength. The value of g on Earth is 9.8 N/kg (approximately 10 N/kg).

 

The relationship between net force (Fnet), mass (m) and acceleration (a) is expressed by the equation:
 
a = Fnet / m