1)Assuming no air resistance, a ball has an acceleration of 10 m s −2 when it is dropped from a window (so its initial speed, when t = 0, is zero). Calculate (i) its speed after 1 s and after 10 s (ii) how far it has fallen after 1 s and after 10 s (iii) how long it takes to fall 20 m. 2. A car starting from rest at traffic lights reaches a speed of 90 km h −1 in 12 s. Find the acceleration of the car (in m s −2 ) and the distance travelled. Write down any assumptions that you have made.