Bells University of Technology, Ota Phy101 Mechanics Tutorial Questions Assume acceleration due to gravity \( \mathrm{g}=10 \mathrm{~m} / \mathrm{s}^{2} \) 1. A stone strikes the ground with a speed of \( 25 \mathrm{~m} / \mathrm{s} \). (a) from what height was it released. (b) How long was it falling? (c) If the stone is thrown down with a sped of \( 10 \mathrm{~m} / \mathrm{s} \) from the same height, then what will be its speed just before hitting the ground? 2. A ball is thrown upward with a speed of \( 19.6 \mathrm{~m} / \mathrm{s} \). (a) how high does it go until its upward speed decreases to zero. (b) How long does the ball take in this upward trip? (c) How long does the ball take to return to the initial position? (d) What will be its velocity then?

Question ix. An ideal gas is enclosed in a cylinder which has a movable piston. The gas is heated, resulting in an increase in temperature of the gas, and work is done by the gas on the piston so that the presure remains constant. a) Is the work done by the gas negative, positive or zero? b) From a microscopic view, how is the internal energy of the gas molecules affected? c) Is the heat less than, greater than or equal to the work? Explain you answer.

14. A train moving at an average speed of \( 72 \mathrm{~km} / \mathrm{h} \) takes 15 seconds to completely cross a bridge that is 80 metres long (a) Express \( 72 \mathrm{~km} / \mathrm{h} \) in metres per second (b) Find the length of the train in metres ( 2 mk )

A boat is supposed to travel with a velocity vector of \( \langle 40,30\rangle \), but the current has a velocity vector of \( \langle 0,-5\rangle \). What is the boat's actual velocity vector? \( \langle 45,30\rangle \) \( \langle 40,25\rangle \) \( \langle 40,35\rangle \)

El péndulo, de masa \( m \) y largo \( L \), de la figura oscila de modo que la masa describe un movimiento circunferencial uniforme de radio \( R \), con una velocidad tangencial de magnitud \( v \).

A 1 km long goods train is running at a speed of 45 \( \mathrm{~km} / \mathrm{h} \). The time taken by this goods train to pass through a 2 km long tunnel is: \( \begin{array}{ll}\text { (A) } 1 \text { minute } & \text { (B) } 2 \text { minutes } \\ \text { (C) } 3 \text { minutes } & \text { (D) } 4 \text { minutes }\end{array} \)