A child puts a 0.005 kg spitball in a straw and blows into the end so that the net internal pressure against the spitball is 4000 N/m². The effective cross-sectional area of the spitball is 0.000075 m². After 0.2 s, how fast is the spitball traveling?

When rowing downstream consider the following scenario. The current of the water is moving at 2 m/s in the direction you are rowing. The coefficient of drag between your boat and the water is 1.2, the area in contact with the water is 0.1 m2 and the density of the water is 1000 kg/m3. You are moving at a velocity of 4 m/s into a head wind of 4 m/s. Your coefficient of drag between you and the air is 1.4, the area in contact with the air is 0.4 m2 and the density of the air is 1.2 kg/m3. Your goal is to create a net force moving downstream that is equal to 100 N. How much force must you exert with the oar and in what direction to achieve this net force downstream?

Explain the physical meaning of each of the terms in Equation 3. The momentum equations for a rotating shallow homogeneous fluid with a free upper surface (i.e. the shallow water equations) are equation 1 & 2. where u(x, y,t), v(x, y,t) are the velocities on the free surface, and h(x, y,t) is the depthof the free surface.

(6) A nozzle is required to pass 1.5 kg/s of air. The inlet conditions are a zero velocity, a pressure of 350 kPa and a temperature of 425°C. If the air is to expand to 140 kPa, determine the throat area required. Also calculate the exit velocity and exit area if the nozzle efficiency is 95 %. Assume that friction takes place in the diverging part only.