Okay, so they want to basically Increase their grip, and they are taking advantage of the force of friction
By Newton's second law, the net vertical force acting on the object is 0, so that
<em>n</em> - <em>w</em> = 0
where <em>n</em> = magnitude of the normal force of the surface pushing up on the object, and <em>w</em> = weight of the object. Hence <em>n</em> = <em>w</em> = <em>mg</em> = 196 N, where <em>m</em> = 20 kg and <em>g</em> = 9.80 m/s².
The force of static friction exerts up to 80 N on the object, since that's the minimum required force needed to get it moving, which means the coefficient of <u>static</u> friction <em>µ</em> is such that
80 N = <em>µ</em> (196 N) → <em>µ</em> = (80 N)/(196 N) ≈ 0.408
Moving at constant speed, there is a kinetic friction force of 40 N opposing the object's motion, so that the coefficient of <u>kinetic</u> friction <em>ν</em> is
40 N = <em>ν</em> (196 N) → <em>ν</em> = (40 N)/(196 N) ≈ 0.204
And so the closest answer is C.
(Note: <em>µ</em> and <em>ν</em> are the Greek letters mu and nu)
Answer:
12 m
Explanation:
The object is in uniformly accelerated motion, so the distance covered can be found using the following suvat equation:
where
s is the distance
u is the initial velocity
t is the time
a is the acceleration
For this problem,
and
u = 0, since we are considering the first second of motion
So, substituting t = 1 s, we find
Answer:
Answer:
Propotionality is important
Explanation:
Explanation:
Answer:
Rate of change of area will be 
Explanation:
We have given rate of change of radius 
Radius of the circular plate r = 52 cm
Area is given by 
So 
Puting the value of r and 
So rate of change of area will be
