Can someone please show me the work for these two problems? I don\'t understand
ID: 1660706 • Letter: C
Question
Can someone please show me the work for these two problems? I don't understand why they are right but I konw the correct answers are A and C respectively. PLEASE SHOW ALL WORK SO I UNDERSTAND PLEASE. Please show ALL work. Thank you.
a) Suppose you start an antique car by exerting a constant force of 400 N on its crank for 0.250 s. What total angular momentum (defined by torque times time) do you impart to the engine if the handle of the crank is 0.5 m from the pivot and the force is exerted so as to create maximunm torque for the entire time? (You may neglect friction; choose the closest answer.) 07 A) 50 kg m2/s B) 100 kg m2/s C) 200 kg m'/s D) 800 kg m2/s E) 1600 kg m2/s b) One end of a stick with mass m and length & is pivoted on a wall, and the other end rests on a frictionless floor, as shown in the Figure. Let Ft and FR be the vertical components of the forces acting on the left end of the stick and on the right end at the pivot, respectively. Then: A) FL > FR pivot Fr frictionlessExplanation / Answer
a.
Result: (A) 50 Kg.m2/s
Explanation:
we know that , torque is given by :
T = F * d
= 400 N * (0.5 m)
= 200 N.m
The angular momentum can be given by :
M = T*t
= ( 200 N.m) *0.250 s
= 50 kg.m2/s
b.
Result: (C) FL = FR = mg/2
Explanation:
the mass of the stick is m , hence the downward force acting at the middle of stick is : mg
where g is the acceleration due to gravity ,
As given, FL & FR be the vertical components.
according to the equilibrium of forces , we have :
FL + FR = mg
both components would be equal in magnitude hence FL = FR = mg/2