Law’s of Cooling:
Newton's law of cooling is used measure the temperature change of an object of some temperature placed in a place of a different temperature. The law states that dT/dt= k(T-R) where T is the temperature of the object at time t, R is the temperature of the surrounding of the place (constant) and k is a constant of proportionality. This law states that the rate of change of temperature is proportional to the difference between the temperature of the object and that of the surrounding environment.
In order to get the previous equation to something that we can use, we must solve the differential equation. The steps are given below.
1. Separate the variables. Get all the T's on one side and all the t's on the other side. The constants can be on either side. dT/T-R = k dt
2. Anti-differentiate both sides.
Ln( T-R ) = kt - C
3. Leave in the previous form or solve for T.
T= e^kt-C + R
When working with this law, remember that t is the variable, the other letters, R, k, C, are all constants. To find the temperature of the object at a given time, all of the constants first should have numerical values. In some cases of convection, you could apply this law and use it to get whatever it is you need.
Law’s of Universal Gravitation:
Isaac Newton compared the acceleration of the moon to the acceleration of objects on earth believing that gravitational forces were responsible for each other. Newton was able to draw an important conclusion about gravity depending on the certain distance.
Fnet = m • a
Newton knew that the force that caused the apple's acceleration (gravity) must be dependent on the mass of the apple. Since the force acting to cause the apple's downward acceleration also causes the earth's upward acceleration (Newton's third law) that force must also depend on the mass of the earth. The force of gravity acting between the earth and any other object is