When switched on, the grinding machine accelerates from rest to its operating speed of 3550 rev/min in 10 seconds. when switched off, it coasts to rest in 31 seconds. determine the number of revolutions turned during both the startup and shutdown periods. also determine the number of revolutions turned during the first half of each period. assume uniform angular acceleration in both cases.

During start total turns

After half of the time total turns

Total number of turns during it stop

After half of the time total turns

Explanation:

Initially the machine is at rest and then starts rotating with speed 3550 rev/min

now we will have

now we know that it took 10 s to reach the speed

so angular acceleration is given as

now it stops in 31 s so the angular deceleration is given as

now initially number of turn to reach the given speed

number of turns during it stop

Now during startup speed after t = 5 s is given as

now during it stop the speed after half the time is given as

now the number of turns is given as

a.   mass number from atomic number