Answer:
691 m
Explanation:
In these problems the time a ball is in the air is determined by the gravitational acceleration (y-coordinate) and the distance it travels is related to the velocity in the x-coordinate.
First get the x and y components of the initial speed.
Initial speed has a magnitude of 125 and a direction of 30°
speed in x = 125 cos 30° = 108.3 m/s
speed in y = 125 sin 30° = 62.5 m/s
The time it takes to the ball to reach the highest height (when the speed in the y-coordinate is 0) is:
0 = 62.5 - 9.8*t
t = 6.38 s
With the time you can calculate the distance travelled in the x-coordinate at a constant speed of 108.3.
d = vt
d = 108.3 * 6.38
d = 691 m
Answer:
Option"B" is correct.
Explanation:
when a body move with constant velocity then acceleration is zero.
1) Let's call
the speed of the southbound boat, and
the speed of the eastbound boat, which is 3 mph faster than the southbound boat. We can write the law of motion for the two boats:
2) After a time
, the two boats are
apart. Using the laws of motion written at step 1, we can write the distance the two boats covered:
The two boats travelled in perpendicular directions. Therefore, we can imagine the distance between them (45 mi) being the hypotenuse of a triangle, of which
and
are the two sides. Therefore, we can use Pythagorean theorem and write:
Solving this, we find two solutions. Discarding the negative solution, we have
, which is the speed of the southbound boat.
The net or resultant force acting on an object is equal to the rate of change of momentum. We can therefore say that because a net force causes an object to change its motion, it also causes its momentum to change with it.