In this question use g=9.8 m s−2g = 9.8 \text{ m s}^{-2}g=9.8 m s−2.
A research probe is ejected from a cliff-side laboratory located 15 metres above a frozen lake. The probe is launched with an initial speed of 18 m s-1 at an angle of 25∘ 25^\circ\,25∘ above the horizontal.
Exactly 0.8 seconds after the probe is launched, a motorized recovery sled, initially at rest on the ice directly below the launch point, begins to accelerate uniformly at a m s−2a \text{ m s}^{-2}a m s−2 in a straight line across the lake. The sled has a collection net positioned at a constant height of 2 metres above the ice.
The sled intercepts the probe when the probe falls into the collection net.
Find aaa. Give your answer to 3 significant figures.