# Physics...NEED HELP

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Physics help. what are the steps to solving the following problems?

Attack on the ice fortress! A comic book villain has taken shelter in an ice fortress in an attempt to hide from the Avengers. Apparently, though, only the Hulk and some guy with a cannon are available to try to extract the bad guy. The walls of the ice fortress are 0.50m thick, and the tensile strength of ice at 0°C is 1.7 x 106 Pa.

a) If the Hulk's fist has a diameter of 6.0 x 101 cm, with how much force will he need to punch the ice wall to make a fist-sized hole? Assume that his fist is a circle where it makes contact with the wall.

b) We fire four iron cannonballs that make it through the wall, but come to a complete stop upon doing so. The cannonballs land in a very small reservoir of water. The cannonballs are heated before being shot and are still at 182°C when they land in 4.00 liters of water that is at 0.0°C. The cannonballs are 15.2 cm in diameter. Do the cannonballs provide enough heat to turn the water into steam? If so, how much steam is produced (in kg)? If not, what is the final temperature of the water and cannonballs?
(Possibly useful information: density of iron, 7.86 x 103 kg/m3; density of water, 1.00 x 103 kg/m3 ; specific heat of water, 4186 J/kg•°C; specific heat of iron, 448 J/kg•°C; latent heat of fusion of water,
2.26 x 106 J/kg)

c) What is the buoyant force on any one of the four cannonballs if it is completely submerged in water? The values you need to solve this are given earlier in the problem.