5. A position-time graph for a particle moving along the xaxis is shown in Figure 2.5: (a) Find the average velocity in the time interval / - 1.50 s to r = 4.00 s. (b) Determine the instantaneous velocity at 1 = 2.00 s by measuring the slope of the tangent line shown in the graph. (c) At what value of tis the velocity zero? * (m) 12 10 8 6. 4 2 0 1 2 3 4 5 6 t(s) Figure P2.5​

A500g object falls off a cliff and losers 100 j from its gravitational potential energy store. if the gravitational field strength g=9.8n/kg, how high is the cliff?

Acoal-fired plant generates 600 mw of electric power. the plant uses 4.8 x 10^6 kg of coal each day, and the heat of combustion of coal is 3.3x 10^7 j/kg. the steam that drives the turbines is at a temperature of 300° c, and the exhaust water is at 37° c. (a) what is the overall efficiency of the plant for generating electric power? (b) how much thermal energy is exhausted each day? (c) what is the change in entropy of the universe for this heat engine? (d) using the same heat reservoirs, what is the maximum possible (carnot) efficiency for a heat engine?

Awoman stands a distance d from a loud motor that emits sound uniformly in all directions. the sound intensity at her position is an uncomfortable 2.0×10-3 w/m2. at a distance 2.6 times as far from the motor, what are (a) the sound intensity and (b) the sound intensity level relative to the threshold of hearing?