Why it is some times possible to loosen caps on screw top bottles by dipping the cap briefly in hot water?

Part a constants huck finn walks at a speed of 0.60 m/s across his raft (that is, he walks perpendicular to the raft's motion what is huck's velocity (speed and direction) relative to the river bank? express your answer to three significant figures and include the appropriate units. relative to the shore)

Amass weighing 24 pounds, attached to the end of a spring, stretches it 4 inches. initially, the mass is released from rest from a point 8 inches below the equilibrium position. find the equation of motion. (use g = 32 ft/s2 for the acceleration due to gravity.)

The temperature in gavin's oven is a sinusoidal function of time. gavin sets his oven so that it has a maximum temperature of 280°f and a minimum temperature of 240°. once the temperature hits 280°, it takes 20 minutes before it is 280° again. gavin's cake needs to be in the oven for 30 minutes at temperatures at or above 270°. he puts the cake into the oven when it is at 260° and rising. how long will gavin need to leave the cake in the oven? (round your answer to the nearest minute.)