7.5 I think because it can not be 9 because it’s not close to 50
Explanation:
It is given that,
Force applied to object, 
Position,
(b) The cross product of force and position vector is used to find the net torque about the z axis. It is given by :



or

The torque is acting in -z axis.
(a) The magnitude of torque is given by :


Hence, this is the required solution.
Answer:
Explanation:
Given that
Superelation= 0.08ft/ft
Given curve= u•
Curve junction factor= 0.13
DR= 5729.57795
R = 5729.57795/D
R = 5729.57795/4
R = 1432.4ft
c + f = V^2/gG
0.08 + 0.13 = V^2 / (32*1432.4)
V^2 = 9625.728 or V = 98 ft/sec
The designed speed for a project considered is a minimum value which means the highway design elements will meet or exceed the standards for the design speed. The maximum safe speed under normal condition is significantly greater than design speed
Infared = used by police
gamma = short wavelength
radio = largest wavelength
visible = only ones we can see