Hello, I would like some help of these two questions. They are from the MEI Mechanics 1 Constant acceleration, Section 2:Further Examples sheet so if anyone has the answers for the whole sheet where I could work backwards that would be more helpful. Thanks in advance.
4. A train is brought to rest with uniform retardation. It travels 30m in the first 2 seconds, and a further 30m in the next 4 seconds. Find
(i) the initial velocity,
(ii) the retardation,
(iii) total time to come to rest
7. A stone is dropped from the top of a cliff and a second later a 2nd stone is thrown vertically downwards at 15m/s. Both stones reach the bottom at the same time. How high is the cliff?