A ship anchored in a port has a ladder which hangs over the side. The length of the ladder is 200cm, the distance between each rung in 20cm and the bottom rung touches the water. The tide rises at a rate of 10cm an hour. When will the water reach the fifth rung?

When the tide rises, the water level will also rise, causing the ladder to rise with it. Since the ladder is 200cm long and the distance between each rung is 20cm, there are a total of 10 rungs on the ladder.Initially, the bottom rung touches the water, so the water level is at 0cm. As the tide rises at a rate of 10cm per hour, the water level will reach the first rung after 1 hour, the second rung after 2 hours, and so on.To find out when the water will reach the fifth rung, we need to calculate how many hours it will take for the water level to rise to 80cm (4 rungs x 20cm each).Since the tide rises at a rate of 10cm per hour, it will take 8 hours (80cm / 10cm per hour) for the water to reach the fifth rung.

A boat travels downstream from A to B, halts for 5 minutes at B, then travels upstream to C. The entire trip takes 4 hrs. Had the boat travelled the entire distance in still water, the boat would have taken 4 hrs. If the speed of the boat in still water and the speed of the stream are 10 km/hr and 2 km/hr respectively, find BC (in km).

A boat sailing through a river moved eastward for 5 km, then cross the river by moving 3 km southward. On reaching the other side it moved westward through 1 km and reached the dock. Find the distance covered by the boat in km.

A boat is pulled into a dock by a rope attached to the bow of the boat and passing through a pulley on the dock that is 1 m higher than the bow of the boat. If the rope is pulled in at a rate of 1 m/s, how fast (in m/s) is the boat approaching the dock when it is 5 m from the dock? (Round your answer to two decimal places.)

22 A transverse water wave is moving along the surface of some water. This causes a ball to movevertically without moving horizontally as it floats upon the surface. At one instant, the ball is at theposition shown.2.4 m0.70 mballdirection ofwave travelNOT TOSCALEThe wave has a frequency of 0.20 Hz and an amplitude of 0.70 m. The distance between a troughand an adjacent peak is 2.4 m.What is the distance travelled by the ball in a time of 20 s?A 5.6 m B 9.6 m C 11.2 m D 19.2 m23 A sound wave travels from left to right across a room. The variation with distance across theroom of the displacement of the air molecules at one instant is shown.At which distance will the air pressure be lowest?displacementdistance from left-handend of roomrightleft0A B C D24 A source emits a sound wave of a single frequency. The Doppler effect causes a differentfrequency of sound to be heard by a stationary observer.What is a requirement for the Doppler effect to occur?A a source that is moving as it produces the sound waveB a source that produces a polarised sound waveC a source that produces a sound wave of changing amplitudeD a source that produces a sound wave of changing frequency