Answer:
0.25miles/min
Explanation:
Instantaneous speed of a person or an object is its speed at a particular moment usually at a period of time.
The speedometer of a car reports the instantaneous speed.
It can be mathematically expressed as;
Instantaneous speed = 
At 20min the distance covered is 5miles;
Instantaneous speed =
= 0.25miles/min
Answer:
The distance is 0.53 m.
Explanation:
Given that,
Target distance = 100.0 m
Speed of bullet = 300 m/s
We need to calculate the total time
Using formula of time

Put the value into the formula


Now, consider vertical motion of bullet.
Initial velocity of bullet in vertical direction = 0 m/s
We need to calculate the vertically distance
Using equation of motion

Put the value in the equation


Hence, The distance is 0.53 m.
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Answer:
Explanation:
A )
At the bottom of the circle , the potential energy of the stopper is converted into kinetic energy
1/2 m V² = mg x 2r + 1/2 mv²
m is mass of stopper , V is velocity at the bottom , r is radius of the circular path which is length of the string , v is velocity at the top
1/2 V² = g x 2r + 1/2 v²
V² = g x 4r + v²
V² = 9.8 x 4 + 8²
V² = 103.2
V = 10.16 m/s
B )
If T be the tension at the top
Net downward force
= mg + T . This force provides centripetal force for the circular motion
mg +T = mv² / r
T = mv²/r -mg
= m ( v²/r - g )
= .005 ( 8²/1 -g )
= .005 x 54.2
= .27 N .
C ) At the bottom
Net force = T - mg , T is tension at the bottom , V is velocity at bottom
T-mg = mV²/r
T = m ( V²/r +g )
= .005 ( 10.16²/1 +9.8)
= .005 x 113
= .56 N .