Answer: T= 715 N
Explanation:
The only external force (neglecting gravity) acting on the swinging mass, is the centripetal force, which. in this case, is represented by the tension in the string, so we can say:
T = mv² / r
At the moment that the mass be released, it wil continue moving in a straight line at the same tangential speed that it had just an instant before, which is the same speed included in the centripetal force expression.
So the kinetic energy will be the following:
K = 1/2 m v² = 15. 0 J
Solving for v², and replacing in the expression for T:
T = 1.9 Kg (3.97)² m²/s² / 0.042 m = 715 N
P=change in E/t
Change in E=p*t
=15*3
=45
The answer is 45J.
Answer:
car is moving away its direction is negative.
the speed must also be negative.
speed this distance decreases the acceleration is negative and if the speed is increasing the acceleration is positive.
Explanation:
In the exercise they indicate that the direction to the motion sensor is positive, as they indicate that the car is moving away its direction is negative.
The speed of the car is
v = (x₂-x₁) / t
As the positions are negative, and the car moves away the speed must also be negative.
The analysis for acceleration must be very careful if the speed this distance decreases the acceleration is negative and if the speed is increasing the acceleration is positive.
In my opinion, i think the first one is the best one since we're cutting down on paper wasted in mails when its better to do it online.
"paying bills online instead of sending paper through mail"
Answer:
That when you leave the ice setting without foil, it melts slower. When you put the piece of ice in the foil it melts faster than just letting it set without foil. I really hope this helps.
Explanation: