Why shouldn't technicians use oxygen or compressed air to pressurize appliances to check for leaks?

Work out sian speed for the first 30 minutes of her journey. give your answer in km/h.

The necleus of an atom is made up of what subatomic particles?

Asolid cylinder and a cylindrical shell have the same mass, same radius, and turn on frictionless, horizontal axles. the cylindrical shell has light-weight spokes connecting the shell to the axle. a rope is wrapped around each cylinder and tied to blocks of equal masses that are held the same height above the ground. both blocks are released simultaneously. the ropes do not slip. which block hits the ground first? or is it a tie?