physics

 A spring has a spring constant of 120 newtons per meter. How much potential energy is stored in the spring as it is stretched .20 meter? 

A. 1.2 J
*B. 2.4 J 
C. 3.1 J
D. 7.4 J

 A distance of 1.0 x 103 separates the charge at the bottom of the cloud and the ground. The electric field intensity between the bottom of the cloud and the ground is 2..0 x 104 newtons per coulomb. What is the potential difference between the bottom of the cloud and the ground? 

A. 1.4 x 104 V
B. 2.5 x 103 V
C. 2.8 x 106 V
*D. 2.0 x 107 V 

 When Adam drinks cold water, his body warms the water until thermal equilibrium is reached. If he drinks six glasses (2.5 kilograms) of water at 0 degrees Celsius in a day, approximately how much energy must his body expend to raise the temperature of this water to his body's temperature of 37 degrees Celsius? 

A. 210 kJ
B. 305 kJ
*C. 390 kJ 
D. 414 kJ