5 A straight slope of length 60 m is inclined at an angle of \(12 ^ { \circ }\) to the horizontal. A bobsled starts at the top of the slope with a speed of \(5 \mathrm {~ms} ^ { - 1 }\). The bobsled slides directly down the slope.
- It is given that there is no resistance to the bobsled's motion.
Find its speed when it reaches the bottom of the slope.
- It is given instead that the coefficient of friction between the bobsled and the slope is 0.03 .
Find the time that it takes for the bobsled to reach the bottom of the slope.