Which of the following is an example of a chemical change?

Boiling water

Burning paper

Dissolving sugar in water

Melting gold

An object has a mass of 15 kg and is accelerating to the right at 16.3 m/s2. The free-body diagram shows the horizontal forces acting on the object. What is the frictional force, Ff, acting on the object? 5.5 N 15 N 244.5 N 494.5 N Answer: 5.5 N

a. A rectangular pen is built with one side against a barn. 1900 m of fencing are used for the other three sides of the pen. What dimensions maximize the area of the pen? b.

Which of the following is an advantage of geothermal energy? a. Scarcity of suitable sites b. Odor pollution c. Low land use d. Possible depletion of reservoirs

Determine the kinetic energy of a toy car with a mass 1.00 kg and a velocity of 2.00m/s

The horizontal component of force acting at an angle of 30 degree with the horizontal is 100N. Find the magnitude of the force and its vertical component.

If the mass of a material is 77 grams and the volume of the material is 19 cm3, what would the density of the material be

A bicyclist is in a 50-km race. She says she had an average velocity of 35. What is missing in the cyclist's velocity? A. units only B. units and distance C. direction only D. units and direction

Which one of the following statements concerning emf is true? A) Emf is the work done in moving the current from one terminal to the other of an emf device.

A fan is a complex machine? True or false?

Which force does not operate at a distance of 1 m? A. Weak nuclear O B. Electric C. Gravitational D. Magnetic