1. While chopping down his father's cherry tree, George discovered that if he swung the axe with a speed of 25 m/s, it would embed itself 2.3 cm into the tree before coming to a stop
a) If the axe head had a mass of 2.5 kg, how much force was the tree exerting on the axe head upon impact? Explain your answer.
>>>I have no idea how to do this...
b) How much force did the axe exert back on the tree? Explain your answer.
>>>I have no idea how to do this either......
2. Jackson's favorite ride in Disneyland is the rollercoaster. The rollercoaster car and passengers have a combined mass of 1620 kg, and they descend the first hill at an angle for 45.0 degrees to the horizontal. With what force is the rollercoaster pulled down the hill?
>>I need help with this... T__T
2007-10-30 06:49:49 · 3 answers · asked by Anonymous in Science & Mathematics ➔ Physics
How do I google the questions?
2007-10-30 06:54:36 · update #1
well you are better off with a physics major answering, it's been a long time since i took it in college. but here are my GUESSES here, based on what I remember.
1a. Force = mass * acceleration. you know the mass (2.5kg). The acceleration can be derived; it is velocity/time. You know the speed was 25 m/s. you know it went in 2.3cm. do the math to find out how much time it would take to cover 2.3cm if it is going at 25 m/s, that is the time it takes to go from 25 m/s to zero. then you have the acceleration and you can solve for Force.
1b. isn't it like newtons first or second or something law, every action has an EQUAL and opposite reaction etc? should be the answer to #1 I am guessing.
2. again Force=mass*acceleration, you have the force and accel is gravity, so 9.8 m/s/s or whatever G is, can't remember anymore. since it is at a 45 degree angle, only 1/2 of the force is pulling it down, the rest is sending it forward. divide F by 2.
2007-10-30 07:00:34 · answer #1 · answered by Mad Ned 2 · 0⤊ 0⤋
1a. The axe decelerates from 25 m/sec to 0 m/sec in 2.3 cm. The average velocity will be 13 m/sec. (All answers to 2 sig figs) ...Therefore:
...t = 0.023/13 = 0.0018 sec
...a = dv/dt = -25/0.0018 = 14000 m/sec²
...F = ma = 25*14000 = 350,000 N...well that can't be right, but I can't see where I went wrong for the life of me
1b. Same as 1a.
2. 1680 * 9.8 sin45 = 11600 N (3 sig figs)
2007-10-30 07:14:44 · answer #2 · answered by gebobs 6 · 0⤊ 0⤋
just type in google the questions i mean dont be lazy
2007-10-30 06:52:43 · answer #3 · answered by Anonymous · 0⤊ 0⤋