The theory of gas flow through small diameter tubes at low pressures is an important consideration of high vacuum techniques.
One equation used in this theory is:
Q =
Where k is a unitless constant, r is the radius of the tube, p1 and p2 are the pressures at each end of the tube, L is the length of the tube, M is the molar mass of the gas, R is the molar gas constant and T is the thermodynamic temperature of the gas.
When a constant braking force is applied to a vehicle moving at speed v, the distance d moved by the vehicle as it comes to rest is given by the expression:
d = kv2
In this equation, k is a constant.
When d is measured in metres and v is measured in metres per second, the constant has a value of k1.
What is the value of the constant when the distance is measured in metres, and the speed is measured in kilometres per hour?