Answer:
C. 100 mph west
Explanation:
Average velocity is total displacement over total time. During the first hour, the average velocity is:
v_avg = 100 mi / 1 hr
v_avg = 100 mph west
Since the velocity is constant, the instantaneous velocity at any time equals the average velocity.
v = v_avg
v = 100 mph west
The force required to start an object sliding across a uniform horizontal surface is larger than the force required to keep the object sliding at a constant velocity once it starts.
The magnitudes of the required forces are different in these situations because the force of kinetic friction is less than the force of static friction. <em>(d)</em>
Answer:
The box should be placed at a distance of 
from the pivot
Explanation:
In order to be in static equilibrium, both Torques have to be the same magnitude, so:
Replacing the formula for Torque:
where X is the distance we need to find.
Solving for X we get:
As we can see, the distance does not depend on the actual value of the mass but on the fact of one being twice as much as the other one.
Answer:
The resultant vector has a magnitude of 4998 m and a direction of 45.7°.
Explanation:
The x component of the resultant vector is the sum of the x components of each individual vector.
x = 3250 cos 38.4 + 1822 cos 58.8
x = 3490.8
Similarly, the y component of the resultant vector is the sum of the y components of each individual vector.
y = 3250 sin 38.4 + 1822 sin 58.8
y = 3577.2
The magnitude can be found with Pythagorean theorem:
√(x² + y²)
√(3490.8² + 3577.2²)
4998
The direction can be found with trigonometry:
atan(y / x)
atan(3577.2 / 3490.8)
45.7°
The resultant vector has a magnitude of 4998 m and a direction of 45.7°.
