Air Rockets can be a fun way of investigating forces. When a air rocket is launched compressed air forces the cardboard rocket off the launcher and up into the air.
• Name the forces acting on the rocket at the top of it's flight.
. Are the forces at the top of the flight balenced or unbalenced?
• Describe how the size and direction of the air resistance force changes during flight, an state
the definition of friction.

Next a skier is pulled by a tow rope up a frictionless ski slope that makes an angle of 15 with the horizontal. the rope moves parallel to the slope with a constant speed of 0.69 m/s. the force of the rope does 800 3 of work on the skier as the skier moves a distance of 8.4 m up the incline. (a) if the rope moved with a constant speed of 2.2 m/s how much work would the force of the rope do on the skier as the skler moved a distance of 8.4 m up the incline? at what rate is the force of the rope doing work on the skier when the rope moves with a speed of (b) 0.69 m/s and (c) 2.2 m/s?

An object weigh 40n in air ,weigh 20n when submerged in water, and 30n when submerged in a liquid of unknown liquid density. what is the density of unknown of liquid?

Which compound is held together by the electrostatic force between two ions? a. co2 b. cci4 c. h2s d. mgf2