-- A balloon containing 600 cm? of air at a pressure of 0,828 kPa escapes from a child's hand in a shopping centre. It rises and when it reaches the roof, the volume has increased to 700 čm. Calculate the pressure on the balloon at this height. (assume that the temperature in the shopping centre remains constant).

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 .