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Questions in physics

📝 Answered - Two balls, each with a mass of 0.844 kg, exert a gravitational force of [tex]8.45 \times 10^{-11} \, \text{N}[/tex] on each other. How far apart are the balls? The value of the universal gravitational constant is [tex]6.673 \times 10^{-11} \, \text{N m}^2/\text{kg}^2[/tex].

📝 Answered - What energy transformations occur in a Ferris wheel?

📝 Answered - The cheetah, which is the fastest land mammal, can accelerate from 0.0 mi/hr to 70.0 mi/hr in 3.0 seconds. What is the acceleration of the cheetah? Give your answer in units of mph/sec.

📝 Answered - Imagine two artificial satellites orbiting Earth at the same distance. One satellite has a greater mass than the other. Which of the following would be true about their motion? A. The satellite with the greater mass is being pulled toward Earth with less of a force than the other satellite. B. The satellite with the greater mass is being pulled toward Earth with a greater force than the other. C. The two satellites are being pulled with equal force by the moon. D. The two satellites are being pulled toward Earth with equal force. Imagine two artificial satellites with equal masses orbiting Earth. One satellite is orbiting closer to Earth than the other. Which of the following would be true about their motions? A. The satellite closer to Earth will be pulled toward Earth with the same gravitational pull as the other satellite. B. The satellite closer to Earth will be pulled toward Earth with less gravitational pull than the other satellite. C. Both satellites will be pulled with equal force toward the moon. D. The satellite closer to Earth will be pulled toward Earth with more gravitational pull than the other satellite. How will resistance change when the voltage increases in an electric circuit if the current remains constant? A. It will decrease. B. It will stay the same. C. It will increase. D. It will decrease, then increase.

📝 Answered - A toaster oven uses 67,500 joules of energy in 45 seconds to toast a piece of bread. What is the power of the oven?

📝 Answered - An oscillator makes 360 vibrations in 3 minutes. a. How many vibrations does it make in one minute? b. How many vibrations does it make in one second? c. What is its period in seconds? d. What is its frequency in hertz?

📝 Answered - At 400 K, a volume of gas has a pressure of 0.40 atmospheres. What is the pressure of this gas at 273 K?

📝 Answered - It takes 56.5 kilojoules of energy to raise the temperature of 150 milliliters of water from 5°C to 95°C. If you use an electric water heater that is 60% efficient, how many kilojoules of electrical energy will the heater actually use by the time the water reaches its final temperature?

📝 Answered - At about 55 meters/sec, a falling parachuter (before the parachute opens) no longer accelerates due to air friction opposing acceleration. Although the effect of air friction begins gradually, imagine that the parachuter is in free fall until terminal speed (the constant falling speed) is reached. How long would it take to reach terminal speed?

📝 Answered - What is the mass of a pure platinum disk with a volume of [tex]113 \, \text{cm}^3[/tex]? The density of platinum is [tex]21.4 \, \text{g/cm}^3[/tex]. Give your answer in grams and kilograms.