7. a force of 100 n acting on a body gives it a speed of 200 m/s in 2
sec. what is the mass of the body?
a. 1kg
b. 5 kg
c. 10kg
d. 15kg

Choice a. 1 kg, assuming that all other forces on the object (if any) are balanced.

Explanation:

By Newton's Second Law,

,

where

As a result,

.

Assume that all other forces on this object are balanced. The net force on the object will be . The net force is constant. Acceleration should also be constant and the same as the average acceleration in the two seconds.

.

.

.

probably not if net force is zero

answer: the metamorphic rocks are formed when they are exposed to high pressure and high temperatures. this happens when one of the earth's plates comes in contact with the other plate by traveling in opposite directions, straight into each other or slipping under one another. the friction that is caused by this activity results in   melting of rocks and when it cools they are known as metamorphic rocks. this process needs a controlled amount of pressure and temperature otherwise it may turn into magma.