Answer:D
Explanation:
Given
Force required to move a box at steady rate is F=78 N
Weight of Block W=150 N
If the block is moving at a steady rate then net Force acting on it is zero
Applied Force must balance the Friction force
where N=normal Reaction
Normal reaction must be equal to weight
The mechanical advantage of the crowbar is
(output force) divided by (input force) .
According to the gripping scenario, that's (750N) / (50N) = <em>15</em> .
Yasher koach, Yosef !
Answer:
Same direction to produce maximum magnitude and opposite direction to produce minimum magnitude
Explanation:
Let a be the angle between vectors A and B. Generally when we add A to B, we can split A into 2 sub vectors, 1 parallel to B and the other perpendicular to B.
Also let A and B be the magnitude of vector A and B, respectively.
We have the parallel component after addition be
Acos(a) + B
And the perpendicular component after addition be
Asin(a)
The magnitude of the resulting vector would be
As A and B are fixed, the equation above is maximum when cos(a) = 1, meaning a = 0 degree and vector A and B are in the same direction, and minimum with cos(a) = -1, meaning a = 180 degree and vector A and B are in opposite direction.
Answer:
Explanation:
PE = mgh where m is mass, g is the pull of gravity, and h is the height to which the object can possibly fall.
PE = 3.0(-9.8)(-12.4) so
PE = 360 J, rounded to the correct number of sig figs.
Answer:
.
Explanation:
The box is sliding with a constant speed in a fixed direction (to the right.) In other words the velocity of this box is constant. Hence, this box would be in a translational equilibrium. The acceleration of this box would be zero.
By Newton's Second Law of motion, the net force on this box would be . In other words, forces on this box are balanced.
The question is asking for the size of the friction on the box. Assuming that the floor is horizontal. The friction on this box would also be horizontal,
The only other force that could balance that friction would be the push to the right. The direction of this push is horizontal (to the right.) Hence, the entirety of that would be in the horizontal direction.
Thus, forces on this box in the horizontal direction would be:
- The push to the right.
- Friction that opposes the rightward motion of the box (that is, to the left.)
Since these two forces must balance each other, the size of the friction would also be .