You are pulling a friend on a sled with a constant velocity using a rope held horizontally in the snow. Using a spring scale attached to the rope, you
measure the tension to be 112 N. The combined mass of the sled and your
friend is 57.4 kg. Write the surface force the ground exerts on the sled in
component form, and determine its magnitude.

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?

What is the average speed of a car that travels 40 mph for 1 hour and 60 mph in another hour?

What practical value did astronomy offer to ancient civilizations?