Considering that a food calorie is equal to about 4 kJ of energy, you wonder how the amount of energy in a serving size of your favorite food compares in other situations. For example, how does this compare to the amount of energy that’s necessary to lift a fully-loaded pickup truck up three meters above the ground? Let’s say the truck has a mass of 2500 kg.

Samir watches a 100-minute movie on his spaceship. maria's spaceshipe flies in the same direction as samir's spaceship but she observes his move to last 125 minutes and his spaceship to be 40 m long. how long does samir observe his own spaceship to be? according to an observer on earth, planet x is stationary. maria and samir depart earth on their spaceships at the same time, each flying at 0.5c. maria flies toward planet x and samir flies in the opposite direction. according to maria, her voyage to planet x takes 9 years. how many years does marias voyage take according to samir?