Answer:
17. .343 seconds: 18.a .357: 18.b 64.5N
Step-by-step explanation:
17. Since there is no friction, we can apply Newton's equation:
We can then use the kinematic equation:
Solve for t:
18.a We can use the friction formula:
Solving for kinetic friction of block mass 7kg:
18.b We should add all forces that will counteract the rightward acceleration.
Use Newton's equation:
Solve for