Question

The propeller on a boat motor is initially rotating at 8 revolutions per second. As the boat captain reduces the boat speed, the propeller SLOWS at a steady rate of 0.9 revolutions per second per second. After 17 revolutions, how fast is the propeller spinning in revolutions per second

Answer 1

Answer:
`5.77\ rps`

Step-by-step explanation:

Given

Initial angular velocity is
`\omega_i=8\ rps`

rate of reduction
`\alpha=0.9 rev/s^2`

after 17 revolution i.e.
`\theta =17\ rev`

using
`\Rightarrow \omega_f^2-\omega_i^2=2\alpha\theta`

Insert the values

`\Rightarrow \omega_f^2=8^2-2* (0.9)*17\\\Rightarrow \omega_f^2=33.4\\\Rightarrow \omega_f=5.77\ rps`