Describe how a convection current is produced.

Can you make sunglasses from new 3D-glasses?

A 95 N force exerted at the end of a 0.50 m long torque wrench gives rise to a torque of 15 N · m. What is the angle (assumed to be less than 90°) between the wrench handle and the direction of the applied force?

The electric force between two charged balloons is 0.12 newtons. If the distance between the two balloons is halved, what will be the new force?

A horizontal force of 200N is applied to a 55kg cart across a 10m level surface. If the cart accelerates at 2.0m/s^2, then what is the work done by the force of friction as it slows the motion of the cart?

A substance has a density of 13.5 g/cm3. What is the volume of a 50 g block of this substance?

A heavy rope, 50 ft long, weighs 0.5 lb/ft and hangs over the edge of a building 120 ft high. how much work is done (in ft-lb) in pulling half the rope to the top of the building?

Does adding a neutron to an atom's nucleus makes it an ion?

What is the difference between a fault-block and upwarped mountains?

Which of the following is not one of the reasons to properly warm up before exercising? A. Develop overall flexibility. B. Increase blood flow to the muscles and raise body temperature. C. Prevent injuries such as strains sprains and muscle cramps.

you are not chilly when swimming in warm water. but when emerging from warm water on a warm summer day, you feel chilly if the wind is blowing. Explain