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1. ### Heat and Phase change: latent heat

Homework Statement A woman finds the front windshield of her car covered with ice at -12.8°C. The ice has a thickness of 4.60 10-4 m, and the windshield has an area of 1.25 m2. The density of ice is 917 kg/m3. How much heat is required to melt the ice? Homework Equations Q=mL or change...
2. ### Temperature conversion

Homework Statement On the moon the surface temperature ranges from 371 K during the day to 1.09 102 K at night. (a) What are these temperatures on the Celsius scale? (b) What are these temperatures on the Fahrenheit scale? Homework Equations T=Tc+273.15 T=Kelvin temperature Tc=Celcius...
3. ### Need a little help!

Homework Statement A computer is reading data from a rotating CD-ROM. At a point that is 0.030 m from the center of the disc, the centripetal acceleration is 118 m/s2. What is the centripetal acceleration at a point that is 0.050 m from the center of the disc? Homework Equations...
4. ### Projectile Velocity

A rocket is fired at a speed of 75.0 m/s from ground level, at an angle of 66.4° above the horizontal. The rocket is fired toward an 11.0 m high wall, which is located 20.0 m away. The rocket attains its launch speed in a negligibly short period of time, after which its engines shut down and the...
5. ### Two Dimensions

A bird watcher meanders through the woods, walking 0.45 km due east, 0.70 km due south, and 2.75 km in a direction 43.0° north of west. The time required for this trip is 2.50 h. (a) Determine the magnitude and direction (relative to due west) of the bird watcher's displacement. Use kilometers...
6. ### Projectile Velocity

A diver springs upward from a board that is three meters above the water. At the instant she contacts the water her speed is 9.00 m/s and her body makes an angle of 81.0° with respect to the horizontal surface of the water. Determine her initial velocity, both magnitude and direction. magnitude...