Part complete a machinist turns the power on to a grinding wheel, which is at rest at time t = 0.00 s. the wheel accelerates uniformly for 10 s and reaches the operating angular velocity of 90 rad/s. the wheel is run at that angular velocity for 29 s and then power is shut off. the wheel decelerates uniformly at 1.8 rad/s2 until the wheel stops. in this situation, the time interval of angular deceleration (slowing down) is closest to:

As we know from the equation of kinematics

here it starts from rest

final angular speed will become 90 rad/s in time interval of t = 10 s

now we will have

So it will stop after 50 seconds of constant deceleration.

work: w = fd (given)

work done by chet   =50*1 = 50 j

work done by mika =40*2 = 80 j

work done by sara =30*1.5 = 45 j

work done by bill =60*0.5 = 30 j

students in order from the greatest amount of work done to the least is mika> chet> sara> bill

hence option (b) is correct.

insects!

explanation: