Three people pull simultaneously on a stubborn donkey. Jack pulls directly ahead of the donkey with a force of 63.1 N, Jill pulls with 64.5 N in a direction 45° to the left, and Jane pulls in a direction 45° to the right with 167 N. (Since the donkey is involved with such uncoordinated people, who can blame it for being stubborn?) Find the magnitude of the net force the people exert on the donkey.

What is the direction of the net force? Express this as the angle from straight ahead between 0° and 90°, with a positive sign for angles to the left and a negative sign for angles to the right.

Note: this questions has two answers.

An object starts from rest at point f and speeds up continuously as it moves around an oval. a. choose a point about 1/8 th of the way around the oval from point f, and label it point g. draw a vector to represent the velocity of the object at point g. b. determine the change in velocity vector   between points f and g.

Askydiver weighing 140 lb (including equipment) falls vertically downward from an altitude of 19,000 ft and opens the parachute after 18 s of free fall. assume that the force of air resistance, which is directed opposite to the velocity, is of magnitude 0.55|v| when the parachute is closed and is of magnitude 14|v| when the parachute is open, where the velocity v is measured in ft/s. assume that acceleration due to gravity has magnitude 32 ft/s/s; remember that weight is the product of mass and gravitational acceleration. (a) find the speed of the skydiver when the parachute opens. (b) find the distance fallen before the parachute opens. (c) what is the limiting velocity vl after the parachute opens? (d) determine how long the sky diver is in the air after the parachute opens. (e) plot the graph of velocity versus time from the beginning of the fall until the skydiver reaches the ground.

Much of the information taught in earth-space science would not be available if it weren’t for our remote sensing abilities. explain two ways our remote sensing strategies contribute to our knowledge of these topics.