Im confused bc im not sure if this is a full question
Answer:
Reflection involves a change in direction of waves when they bounce off a barrier. Refraction of waves involves a change in the direction of waves as they pass from one medium to another.
Explanation:
1250 J in 5 sec= 250 Joule(s) per second (1250/5 0
250 Joules per second = 250 Watts ( 1J/s = 1 Watt per definition)
250 Watts output = 250/0.65 efficiency = 384 Watts input
1 Horsepower = 732 Watts
Motors 1 Horsepower and under are made in certain step sizes like
3/4 , 1/2 , 1/3, 1/4, 1/16 1/20 of a Horsepower.
3/4 Horsepower is 549 Watts
1/2 Horsepower is 366 Watts
so you need to 3/4 horsepower motor to achieve 1250 J of work in 5 seconds.
Answer:
D
Explanation:
From the information given:
The angular speed for the block 
Disk radius (r) = 0.2 m
The block Initial velocity is:
Change in the block's angular speed is:
However, on the disk, moment of inertIa is:
The time t = 10s
∴
Frictional torques by the wall on the disk is:
Finally, the frictional force is calculated as:
