Physics Study Guide
1. A 250.0 g metal block absorbs 7.849 × 10 3 J of heat to raise its
temperature by 35.0 K. What is the substance? Show your work.
Specific Heats of Selected Substances
Substance
Water (ice) C [J/(kg·K)]
2,060 Iron 450 Aluminum 897 Gold 130 Copper 385 Silver 235 Ammonia (liquid) 4,700 Water (liquid) 4,180 Water (steam) 2,020 Lead 2. 128 A 12.0 V battery is hooked up with three resistors (R1, R2, and R3) in parallel
with resistances of 2.5 ?, 7.0 ?, and 15.0 ?, respectively.
a.) Draw a labeled circuit diagram for the circuit described using correct
symbols.
b.) Calculate the equivalent resistance.
c.) Calculate the current passing through each resistor in the circuit. 3. A block and tackle is used to raise a 72.0 N crate 12.3 m from the loading
dock to the ship. This requires a force of 25.0 N to be applied by the
longshoreman.
a.) What is the mechanical advantage of the block and tackle?
b.) How much rope must be pulled? Note: Assume that IMA = MA.
c.) The longshoremen have only a 40 m rope that they are told not to
cut. They use this for the block and tackle. How does this affect the
efficiency of the block and tackle? 4. A 650.0 kg roller coaster car is at rest at the top of a 75 m hill. It rolls down
the first drop to a height of 28 m. When it travels to the top of the second hill,
it is moving at 23.5 m/s. It then rolls down the second hill until it is at ground
level. Draw a picture of the roller coaster drop and calculate the kinetic and
potential energy at the top and bottom of each hill. 5. A 2.4 cm object is 15.0 cm to the left of a convex lens with a focal length of
+5.0 cm.
a.) Draw a ray diagram of the setup showing the location of the image.
b.) Calculate the distance of the image from the lens.
c.) What size is the image and is it upright or inverted? 