The second option rolling friction
Answer:
average force = 385,140 N
Explanation:
from the question we are given the following
mass (m) = 1800 kg
distance of fall (d) = 3 m
driven distance (l) = 14.4 cm = 0.144 m
acceleration due to gravity (g) = 9.8 m/s^{2}
work done = average force x driven distance.....equation 1
and
work done = change in kinetic energy + change in potential energy
work done = (0.5 x m x (v^{2} - u^{2})) + (m x g x (-d-l))
- Initial velocity (u) and final velocity (v) are zero because the pile driver is it rest before it moves to hit the pile and after hitting the pile.
- The changes in length for the potential energy are negative because the pile moves downward
we now have work done = (m x g x (-d-l))...equation 2
now equating the two equations for work done we have
average force x driven distance = (m x g x (-d-l))
average force x 0.144 = 1800 x 9.8 x (-3-0.144)
average force = (1800 x 9.8 x (-3-0.144)) ÷ 0.144
average force = 385,140 N
Correct question:
Manny walked a total of 3 miles. The reference point used to calculate the total distance that he walked was the same as the ending point. Which describes where Manny most likely walked?
a. from the bottom of a hill to the top
b. on a circular nature trail
c. on a sidewalk from his house to the mall
d. from the beginning of a straight track to the end
Answer:
b. on a circular nature trail
Explanation:
As it is mentioned that Manny that his reference point from where she started is same as ending point meaning that she moved in a circular path making point B correct answer.
Dr.phil can help you with that answer also the answer is 21.3
