need explanation pls
A crane machine is used to lift cement slabs of weight w at Delhi metro site. Machine have to lift the slabs from rest and have to put them on the elevated platform at a height ‘h’. If the maximum tension that the cable of crane machine can tolerate is nw (n > 1), then minimum time in which ascent can be done by the machine is (Tmin = 0)
ANS: (2nh/(n-1)g)^1/2
Answers
Explanation:
Question 2: State the principle of machine.
Answer: According to the principle of machine work done by a machine or output work can never be greater than the work done on the machine or input work. In an ideal machine, “the output work of a machine is equal to input work”, is known as principle of a machine.
Question 3: Give an example where a machine is used to obtain gain in speed.
Answer: In automobiles, gear arrangement system (machine) is used to obtain gain in speed.
Question 4: What is the efficiency of an ideal machine?
Answer: The efficiency of an ideal machine is 1 (or 100%).
Question 5: Write an expression to show the relationship between mechanical advantage, velocity ratio and efficiency for a simple machine.
ANS: (2nh/(n-1)g)^1/2