1.  The gravitational attraction between two objects is given by the formula F= G(m_{1}m_{2}/d^{2}) where m represents the masses of the two objects, d is the distance between them and G is the gravitational constant (note: G = 6.67 x 10^{11}m^{3}kg^{1}s^{2}). (a) Calculate the gravitational force between two objects (m_{1}=525,000kg, m_{2}=1,380,000kg) that are separated by70meters. (b) Then determine what the force is if m_{1}is doubled and d is decreased by a factor of1/3(hint: calculate what to subtract first and then subtract from d; do not just multiply d by the fraction).

 2.  Robert calculated the mass of a toy car to be24.3grams. Anthony calculated the mass of the same car but made an error and obtained a mass that was greater than Robert's by a ratio of5to2. What was Anthony's calculation for the mass of the car?


3.  Space ship Z is traveling at179,000miles per second. Spaceship Q is traveling at172,000miles per second. What is the ratio of speeds (Z/Q) of the two spaceships? Express your answer in terms of the maximum speed of light, which is186,000miles per second.

 4.  On planet X, the atmospheric pressure is lower than it is on planet Y. Interplanetary probes were recently sent to the two planets and data were obtained on many things including the atmospheric pressure. The pressure on planet Y is20N/m^{2}. If the pressure on planet X istwothirdsthat of planet Y, what is the pressure, in Pascals, on planet X? Round your answer to the nearest hundredth if necessary.


5.  * Esta es una hoja prehecha. Utilice el enlace arriba de la página para un imprimible. 
 6.  A sealed steel container of methane gas is slowly heated. The temperature increases by5C every30minutes. If the initial temperature was25C, what will the initial to final temperature ratio (T_{i}/T_{f}) be after three hours?

