A carpenter sands a wooden board until it is smooth. Is this a physical or a chemical change?

A student is observing the oscillations of a mass on the end of a spring. The spring has a force constant of 6 x 10-5N/m, and the mass is 0.15 kg. She pulls it 6 cm below equilibrium and lets it go.

What should a free-body diagram look like for a skydiver who has opened his parachute and is now slowing down as he falls? There is an arrow up for air resistance and an arrow down for gravity. The arrow up is longer than the arrow down.

In mammals, the weight of the heart is approximately 0.5% of the total body weight. Write a linear model that gives the heart weight in terms of the whole body weight. Use the model to fins a. the weight of a human whose weight is 183 lbs.

By examining a wave's pattern after it interacts with a barrier or gap, measurements can be made to better understand certain wave phenomena. What is a broad question you can answer by doing this experiment?

Acceleration changes and objects ... a. inertia speed or both b. speed gravity or both c. gravity direction or both d. speed direction or both

Which method is used to counteract the effects of erosion caused by water

Which law explains a soccer player who kicks a ball with his foot and his toes are left stinging?

While a roofer is working on a roof that slants at 39.0 degrees above the horizontal, he accidentally nudges his 88.0 N toolbox, causing it to start sliding downward, starting from rest. If it starts 4.

Suppose that the centripetal force acting on an object in circular motion were doubled to a new value, and the object remained in a circular path with the same radius. How would the motion be affected?

2. Air at a temperature of 20 ºC passes through a pipe with a constant velocity of 40 m/s. The pipe goes through a heat exchanger in which hot gases outside the pipe heat up the air to 820 ºC.