Suppose that two boys pull a sled with forces of 2.0 x 104 N at a 15° angle to the left of the center of the sled, and 1.8 x 104 N at an angle of 25° to the right of the center of the sled, respectively.

If the sled does not move, what is the other force that must be acting on the sled?

a. 2.1 x 104 N at 260°
b. 2.1 x 104 N at 290°
c. 3.6 x 104 N at 266°
d. 3.6 x 104 N at 282°

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.

Aforklift raises a 1,020 n crate 3.50 m up to a shelf. how much work is done by the forklift on the crate? the forklift does j of work on the crate.

Determine the age of a fossil if it had only one eighth of its original carbon-14 content remaining?