can someone HeLp me??

Question

anonymous · Answer

i have 6 Questions please help? .....

1.   A force acting on an object does no work if  (1 point)
a machine is used to move the object.
the force is not in the direction of the object’s motion.
the force is greater than the friction of motion.
the object accelerates.

2.   Which of the following statements is true?  (1 point)
To increase power, you can decrease the amount of work you do in a given amount of time, or you can do a given amount of work in less time.
To increase power, you can decrease the amount of work you do in a given amount of time, or you can do a given amount of work in more time.
To increase power, you can increase the amount of work you do in a given amount of time, or you can do a given amount of work in less time.
To increase power, you can increase the amount of work you do in a given amount of time, or you can do a given amount of work in more time.

3.   How can a machine make work easier for you?  (1 point)
by decreasing the amount of work you do
by changing the direction of your force
by increasing the work done by the machine
none of the above

4.   If you know the input distance and the output distance of a machine, which of the following can you calculate?  (1 point)
work
actual mechanical advantage
efficiency
ideal mechanical advantage

5.   A 120-meter-long ski lift carries skiers from a station at the foot of a slope to a second station 40 m above. What is the IMA (Ideal Mechanical Advantage) of the lift?  (1 point)
0.3
3
40
160

6.   A mechanical device requires 420 J of work to do 230 J of work in lifting a crate. What is the efficiency of the device?  (1 point)
0.5%
190%
55%
183%

anonymous · Answer

Answering the ones I know atm) 1: A.
2:B.
3:A
4:B <-- Wasn't to sure on this one sorry.  xD Doing a Science test atm.. But the other ones were on it so I answered to what I answered from what I know. Hope this helps.