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The percent efficiency of a machine can never be 100% (or greater), because in the real world some energy is always converted into a. heat b. work c. input force d. output force

Which of the following elements is in the same period as phosphorus? a. carbon c. nitrogen b. magnesium d. oxygen select the best answer from the choices provided a b c d

This is important. 1. which of the following is an si base unit for measuring length? (2 points) inch gram meter mole 2. which of the following units for distance is an si unit? (2 points) centimeter foot inch yard 3. which of the following tools should a scientist use to measure an object in meters? (2 points) electronic balance pan balance tape measure thermometer