Answer:

Explanation:
As we know that tension force in the string will be equal to the centripetal force on the string
so we will have

now we have

now we have


now when string length is 0.896 m and its speed is 71.5 m/s then we will have



Answer:
A skater glides along a circular path. She defines a certain point on the circle as her origin. Later on, she passes through a point at which the distance she has traveled along the path from the origin is smaller than the magnitude of her displacement vector from the origin.
So here in circular motion of the skater we can see that the total path length of the skater is along the arc of the circle while we can say that displacement is defined as the shortest distance between initial and final position of the object.
So it is not possible in any circle that arc-length is less than the chord joining the two points on the circle
As we know that arc length is given as

length of chord is given as

so here


so we have

Answer:
D. Newton's first law
Explanation:
Newton's first law of inertia says that an object will remain how it is, unless affected by an outside force. In this case, the plates want to remain stationary(not moving). Therefore, if you pull the table cloth fast enough, the force of friction produced will be small enough so that the Inertia of the plates will overcome the force of friction.
Answer:
Explanation:
Let the radius of track required be r.
Centripetal force will be provided by frictional force which will be equal to
m v²/ r
Frictional force = mg x μ
So
m v² /r = mg μ
r = v² / μ g =
v = 29 km /h = 8.05 m /s
r =( 8.05 x 8.05 ) /( .32 x 9.8 ) = 20.66 m
Answer:
reference against doubt
Explanation:
exact standards of measurement are a reference point for situations in doubt , a line against which to test and observe.