<u>Explanation:</u>
a.
- One user can read the private data of another user-privacy.
- One user can prevent another user from getting anything done-denial of service.
Indeed, in any multiprogramming and time-sharing environment since the computers of users are networked together, then it is very possible for a bad actor to read the private data of another user, or even prevent another user from accessing their computer by employing a denial of service attack on the network. In other words, the network would be unable to handle the request of users since has been overloaded by another user.
b. a. Yes - if we can ensure that the operating system prevents any sharing of data between users, either for reading or writing and fairly shares the computer, then we can achieve the same level of security.
Answer:
15.7 ; 78.5
Explanation:
Mechanical advantage of a screw = Circumference / pitch
Circumference = pi × d
Where :
pi = 3.142, D = diameter
Therefore ;
Circumference = 3.142 × (1/4) = 0.785 in
Pitch = 1/TPI
TPI (thread per inch) = 20
Pitch = 1/ 20 = 0.05
Mechanical advantage = 0.785 / 0.05 = 15.7
Resistance force if effort force is 5lb
Mechanical advantage = Fr / Fe
Fe = effort force, Fr = resistance force
15.7 = Fr / 5
Fr = 15.7 × 5 = 78.5 lbs
