How many types of electrical charges exists

A post is wrapped two full turns around with a belt. The tension in the belt is 7500 N by exerting a force of 150 N on its free end. Determine the coefficient of static friction between the belt and the post.

A spoon can sound like a bell. Explain scientifically in detail.

What role do consumers play in a mixed economy?

Oxygen and nutrients are moved through the body by the: a. circulatory system c. lymphatic system b. digestive system d. reproductive system

If an airplane is flying directly north at 300.0 km/h, and a crosswind is hitting the airplane at 50.0 km/h from the east, what is the airplane's resultant velocity? (Use the graphical method to answer and include your scale on the graph paper.

A taxi hurries for 1 3/4 hours with a constant speed of 84 mph and then for another 1 hour 45 minutes with a constant speed of 24 mph. what is its average speed for the total trip?

A carbon atom has how many valence electrons?

X-rays UV light waves Sound waves Earthquake waves. All of these have which characteristic in common?

V=345m/s, 7210Hz, X=?

As a mercury atom absorbs a photon of energy, an electron in the atom changes from energy level d to energy level e. Determine the energy of the absorbed photon in electronvolts.