How much leg lunges squats push ups and sits ups should a 13 year old boy do a day?

A carbon rod with a radius of 2.1 mm is used to make a resistor. The resistivity of this material is 3.2 * 10-5 Ω · m. What length of the carbon rod should be used to make a 13.7 Ω resistor?

Suppose the displacement x of another object is related to time t according to x = A sin (2nft), where A and f are constants. What are the dimensions of A? a. L x T b. L / T c. L d. T / L e. T

If the phase angle for a block-spring system in SHM is ϕ and the block's position is given by x = xm cos (ωt + ϕ), what is the ratio of the kinetic energy to the potential energy at time t = 0? (Use any variable or symbol stated above as necessary.)

What happens during destructive interference? the crests and troughs of out-of-phase waves cancel each other out the crests and troughs of two waves combine into one larger waveform two waves add their effects to each other waves move in opposite

Which atomic model is missing from this set?

Which of these rocks are formed by volcanic activity? select the two correct answers. a. marble b. basalt c. limestone d. granite e. sandstone

Which source is most likely an authority on the subject? Dr. Vale, a pediatrician, discusses electrical circuitry on her home-improvement website. Jonah, an amateur cook, teaches his son how to make the best grilled cheese sandwiches.

What methods can be used to break down substances into elements

8. A gas is contained in a horizontal piston-cylinder apparatus at a pressure of 350 kPa and a volume of 0.02 m3. Determine the work done by the piston on the gas if the cylinder volume is increased to 0.15 m3 through heating.

A 75.0 kg person stands on a scale in an elevator. (a) What does the scale read (in N and in kg) when the elevator is at rest?