A15 g baseball is thrown with a speed of 25 m/s.(a) What is kinetic energy?(b) How much work was done to reach this speed, starting from rest?

What sort of waves exhibit the doppler effect?

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 .

By what factor does the drag force on a car increase as it goes from 65 to 110 km/h?