(III) Air in a 120-km/h wind strikes head-on the face of abuilding 45 m wide by 75 m high and is brought to rest. Ifair has a mass of 1.3 kg per cubic meter, determine theaverage force of the wind on the building.

A surprising demonstration involves dropping an egg from a third-floor window to land on a foam-rubber pad 2 in (5 cm) thick without breaking. If a 56-gram egg falls 12 m, and the foam pad stops the egg in 6.25 ms, by how much is the pad compressed?

You are consulted by a company to assess the economic potential of the iceberg towing scheme. The company proposes to lasso an iceberg off the coast of Greenland, and tow it 2000km to the South- East of England. (a) Estimate how large an iceberg can feasibly be towed by a 10,000 kW tug-boat at a speed of 1m/s. Take the density of sea-water to be 1025 kg/m'. (b) Estimate how much the iceberg would melt during its journey, if the average sea temperature is 8°C. (c) If the iceberg is sold to the water company at 1p per litre, do you think the scheme is economically feasible? Assume that marine fuel costs 80p per litre, has a calorific content of 35MI per litre, and that the tug's engine efficiency is 30 %.

A flat roof is very susceptible to wind damage during a thunderstorm and/or tornado. If a flat roof has an area of 520 m2 and winds of speed 43.0 m/s blow across it, determine the magnitude of the force exerted on the roof. The density of air is 1.29 kg/m3.

A 105kg man sits on the Stern of a 5.8 m long boat the prow of the boat touches the pier but the boat isn't tied. the man notices his mistake stands up and walks to the boat's prow, but the time he reaches the prow it's moved 2.09 M away from the pier. assuming no water resistance to the boat's motion calculate the boats mass(not counting the man) Answer in units of kg.

Repeat Exercise 5.18 with the contestant pulling the block of ice with a rope over his shoulder at the same angle above the horizontal as shown in Figure 5.23(b).

which is faster in filling a bag with air, at rest or after exercise?

Researchers have found that a gecko’s foot iscovered with hundreds of thousands of small hairs (setae) thatallow it to walk up walls and even across ceilings. A single foot pad,which has an area of 1.0 cm2, can attach to a wall or ceiling with aforce of 11 N. (a) How many 250-g geckos could be suspended fromthe ceiling by a single foot pad? (b) Estimate the force per squarecentimeter that your body exerts on the soles of your shoes, andcompare with the 11 N>cm2 of the sticky gecko foot.

An archer shoots a 0.024-kg arrow at a targetwith a speed of 54 m>s. When it hits the target, it penetrates to a depthof 0.083 m. (a) What was the average force exerted by the target on thearrow? (b) If the mass of the arrow is doubled, and the force exerted bythe target on the arrow remains the same, by what multiplicative factor does the penetration depth change? Explain