A load of 800 N is lifted using a block and tackle having 5 pulleys. If the applied effort is 200 N, calculate i. Mechanical advantage
ii. Velocity ratio
iii. Efficiency
iv. Output work if load is lifted 5m high.
v. Input work

Explanation:

Load=800N

Effort=200N

1. Mechanical Advantage = LOAD/EFFORT

= 800N/200N

= 4

2 Velocity Ratio = no. Of pulleys =5

3. Efficiency = Mechanical advantage / velocity ratio × 100%

= (4/5)×100%

=80%

4. output work= load×load distance

= 800N × 5m

= 4 × 1000J

5. Efficiency = (output work/input work) ×100%

Or, 80% = (4000J/input work) ×100%

Or, 80%/100% = 4000J/inputwork

Or, 4/5 = 4000J/inputwork

Or, input work =4000J × 5/4

Input work = 5×1000J

I hope it helped! ;-)

I got the same answers.

Explanation:

I agree with the first person respone.