A pile of bricks of mass M is being raised to the tenth floor of a building of height H = 4y above the ground by a crane that is on top of the building. During the first part of the lift, the crane lifts the bricks a vertical distance h1=3y in a time t1=4T. During the second part of the lift, the crane lifts the bricks a vertical distance h2=y in t2=T. Which of the following correctly relates the power P1 generated by the crane during the first part of the lift to the power P2 generated by the crane during the second part of the lift? A. P2=4P1
B. P2=43P1
C. P2=P1
D. P2=34P1
E. P2=13P1

The correct option is  B

Explanation:

From the question we are told that

   The mass of the pile is  M

   The  height is  H  =  4 y

    The vertical distance achieve during the first lift is  

     The time taken is  

    The vertical distance achieve during the second lift is  

     The time taken is

Generally the velocity of the crane during the first lift is  

=>        

Generally the velocity of the crane during the second  lift is    

=>      

Generally the power generated by  the crane during the first lift is    

Here is the weight of the brick which is mathematically represented as

      , g is the acceleration due to gravity

 So

Generally the power generated by  the crane during the first lift is    

Here is the weight of the brick which is mathematically represented as

      , g is the acceleration due to gravity

 So

The ratio of the first power generated to the second power is  

=>    

=>  

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

96.77 amp

explanation:

rl = 250/100 = 2.5 ohms.

egl = 250 + (100 × 0.1) + 2 = 262 v.

at 700 r.p.m., eg2 = 262 × 700/1000 = 183.4 v.

if ia is the new current, then eg2 - 2 - (ia × 0.1) = 2.5 ia

which means this will give ia = 96.77 amp.