What is the amount of effort required to lift up 600N load by using a lever of one meter length whose fulcrum is 20cm far from load? Efficiency=75%

112.5N

Explanation: Given that the

Load L = 600N

Distance moved by load = 20cm

Since the lever is one metre, the distance moved by the effort will be

100 cm - 20cm = 80 cm

Efficiency = 75%

Efficiency of a machine is the ratio of the effort multiply by distance covered by the effort to the load multiply by the distance covered by the load as percentage.

75/100 = (effort × 0.8)/ ( 600 × 0.2)

Cross multiply

80 effort = 9000

Effort = 9000/80

Effort = 112.5 N

Therefore,  the amount of effort required to lift up the load is 112.5N

given data:

determine the horse power (h.p) = ?

force applied to move the box(f) = 10 pounds,

box lifted from a distance         (d) = 3 feet

time taken to lift                         (t) = 10 sec,

the horse power is defined as amount of work required to move a load. the horse power is equal to 550 foot-pound per second

                  1 h.p   = 550 foot-pound/second

it can also be defined as the the load that need to be move a body for certain distance in a certain amount of time.

mathematically,

                      h.p = (force × distance)/ time

                            = (10 × 3)/ 10

                            = 30/10

                            = 3 foot -pound/sec

hence, the horse power is needed to move the box is 3 foot-pound/second

important note: 1 h.p = 550 foot-pound/second = 746 watts

when jerome paddle in flowing river towards east the net speed of jerome will increase

so the net speed of jerome will be given as

now the speed of paul will be same as it is given as he is running on the ground

so

so here we can say since the speed of jerome is more so he will win the race

now as we know the distance so the time difference is given as

so jerome will reach first and the time difference will be 203.55 s or 3.4 min