Answer:

Explanation:
Given that,
Heat required, Q = 1200 J
Mass of the object, m = 20 kg
The increase in temperature, 
We need to find the specific heat of the object. The heat required to raise the temperature is given by :

So, the specific heat of the object is
.
Since the temperature decreases (cold) , the pressure exerted will decrease. the particles are move slower and collide less vigorously and frequently with the inner surface of the container . therefore since p = f/a , the pressure will decrease as force exerted decreases .
B. only its velocity should change
Answer:
The path of an object in uniform motion is a straight line.