Một đoàn tàu đang chuyển động với vận tốc 36km/h thì tăng ga chuyển động thẳng nhanh dần đều. Sau 20 giây tàu đạt vận tốc 54km/h. a) Tính gia tốc của đoàn tàu.

b) Tính quãng đường tàu đi được trong thời gian trên.

Agymnast dismounts off the uneven bars in a tuck position with a radius of 0.3m (assume she is a solid sphere) and an angular velocity of 2rev/s. during the dismount she stretches out into the straight position, with a length of 1.5m, (assume she is a uniform rod through the center) for her landing. the gymnast has a mass of 50kg. what is her angular velocity in the straight position?

Which atomic model was proposed as a result of j. j. thomson’s work?

Cathy is pedaling down a steep hill on her bicycle and wants to be able to coast up the next hill, which is 25 meters high, without pedaling. cathy and her bicycle have a mass of 75 kg. assuming her bicycle is 100% efficient, what would her speed have to be?