Time t=2.4 minutes=2.4×60=144 seconds
distance s=1.2 miles=1.2×1609=1930.8 meters
speed v=s/t=1930.8÷144=[tex] \frac{1930.8}{144} = \frac{160.9}{12} =[/13.408m/s ~nearly]
Its a thermometer . i hope this helps you
Answer:
7.5 J
Explanation:
To answer the question given above, we need to determine the energy that will bring about the speed of 1 m/s. This can be obtained as follow:
Mass (m) = 15 Kg
Velocity (v) = 1 m/s
Energy (E) =?
E = ½mv²
E = ½ × 15 × 1²
E = ½ × 15 × 1
E = ½ × 15
E = 7.5 J
Therefore, to change the speed to 1 m/s, the employee must do a work of 7.5 J.
Explanation:
It is given that,
Length of the helicopter, l = 3.1 m
The helicopter rotates, the length of helicopter will become the radius of circular path, r = 3.1 m
Angular speed of the helicopter, ![\omega=280\ rev/min=29.32\ rad/s](https://tex.z-dn.net/?f=%5Comega%3D280%5C%20rev%2Fmin%3D29.32%5C%20rad%2Fs)
(a) The centripetal acceleration in terms of angular velocity is given by :
![a_c=r\times \omega^2](https://tex.z-dn.net/?f=a_c%3Dr%5Ctimes%20%5Comega%5E2)
![a_c=3.1\times (29.32)^2](https://tex.z-dn.net/?f=a_c%3D3.1%5Ctimes%20%2829.32%29%5E2)
![a_c=2664.95\ m/s^2](https://tex.z-dn.net/?f=a_c%3D2664.95%5C%20m%2Fs%5E2)
(b) Let v is the linear speed of the tip. The relation between the linear and angular speed is given by :
![v=r\times \omega](https://tex.z-dn.net/?f=v%3Dr%5Ctimes%20%5Comega)
![v=3.1\times 29.32](https://tex.z-dn.net/?f=v%3D3.1%5Ctimes%2029.32)
v = 90.89 m/s
![\dfrac{v_{tip}}{v_{sound}}=\dfrac{90.89}{340}=0.267](https://tex.z-dn.net/?f=%5Cdfrac%7Bv_%7Btip%7D%7D%7Bv_%7Bsound%7D%7D%3D%5Cdfrac%7B90.89%7D%7B340%7D%3D0.267)
Hence, this is the required solution.