A string pulls horizontally on a cart so that it moves at increasing speed in positive xx-direction along a smooth, frictionless, horizontal surface. At the moment of time t1, when the cart is moving medium-fast, the magnitude of the pulling force is reduced to half its former magnitude. Use a vertical y-axis with a positive direction pointing up.
Draw a force diagram for the cart before the pulling stops.
Draw the vectors starting at the black dot. The location and orientation of the vectors will be graded. The length of the vectors will not be graded.

11. you want to calculate the displacement of an object thrown over a bridge. using -10 m/s2 for acceleration due to gravity, what would be the total displacement of the object if it took 8 seconds before hitting the water?

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?

Describe uniform velocity and variable velocity in short