(b) Quenching is a process used to change the properties of steel by rapidly cooling it
During the quenching process, the steel is heated to a very high temperature and
then placed in a container of cold water.
A steel rod is quenched by heating it to a temperature of 815 °C before placing it in
cold water.
The mass of the steel rod is 15 kg.
The final temperature of the rod and water is 60 °C.
Calculate the energy transferred from the steel rod to the water.
Use the correct equation from the Physics Equation Sheet.
Specific heat capacity of steel = 490 J/kg °C.
Give the answer to two significant figures.
[3 marks]

The car would move to the right with 150 n of force. the 150 n of force from friction and air resistance slows the car from moving to the right with 300 n of force.

Answer///air resistance,drag;

Answertraveling around a circular trackexplanation"traveling around a circular track" is the best answer as you could be traveling around a circular track at a constant speed. your velocity would therefore have the same magnitude but will always be constantly direction. since acceleration is the rate of change of velocity, the rate of change will only involve the direction of velocity and not the magnitude.wrong choices: "an object at rest" does not accelerate at all"increasing speed while traveling around a curve" means that the acceleration will not be constant due to only change in direction; it will be constant due to both magnitude and direction"an object in free fall" does not necessarily change direction 

Decrease the surface area of the object and also decrease the concentration which will allow the particles to collide faster