The mass of a hot air ballon including its cargo is 320 kg. the hot air inside it has a density of 1.19 kg/m^3. the density of the outside air is 1.29 kg/m^3. what is the buoyant force acting on the ballon when it is floating above the ground?

If the wheels lock when braking suddenly the vehicle: a: loses traction b: lose steering wheel ability c: gain speed slightly d: gain steering ability

It's a snowy day and you're pulling a friend along a level road on a sled. you've both been taking physics, so she asks what you think the coefficient of friction between the sled and the snow is. you've been walking at a steady 1.5m/s, and the rope pulls up on the sled at a 32 ∘ angle. you estimate that the mass of the sled, with your friend on it, is 65 kg and that you're pulling with a force of 80 n .

One soccer player (a) is moving at 4 km/h when she kicks the ball while another soccer player (b) is moving at 8 km/h. what statement accurately compares their kinetic energy if they have the same mass? a) both soccer players have the same kinetic energy. b) player b has twice the kinetic energy of player a. c) player b has four times the kinetic energy of player a. d) their kinetic energy can't be compared without knowing their mass.