Answer:
(A) 374.4 J
(B) -332.8 J
(C) 0 J
(D) 41.6 J
(E) 351.8 J
Explanation:
weight of carton (w) = 128 N
angle of inclination (θ) = 30 degrees
force (f) = 72 N
distance (s) = 5.2 m
(A) calculate the work done by the rope
- work done = force x distance x cos θ
- since the rope is parallel to the ramp the angle between the rope and
the ramp θ will be 0
work done = 72 x 5.2 x cos 0
work done by the rope = 374.4 J
(B) calculate the work done by gravity
- the work done by gravity = weight of carton x distance x cos θ
- The weight of the carton = force exerted by the mass of the carton = m x g
- the angle between the force exerted by the weight of the carton and the ramp is 120 degrees.
work done by gravity = 128 x 5.2 x cos 120
work done by gravity = -332.8 J
(C) find the work done by the normal force acting on the ramp
- work done by the normal force = force x distance x cos θ
- the angle between the normal force and the ramp is 90 degrees
work done by the normal force = Fn x distance x cos θ
work done by the normal force = Fn x 5.2 x cos 90
work done by the normal force = Fn x 5.2 x 0
work done by the normal force = 0 J
(D) what is the net work done ?
- The net work done is the addition of the work done by the rope, gravitational force and the normal force
net work done = 374.4 - 332.8 + 0 = 41.6 J
(E) what is the work done by the rope when it is inclined at 50 degrees to the horizontal
- work done by the rope= force x distance x cos θ
- the angle of inclination will be 50 - 30 = 20 degrees, this is because the ramp is inclined at 30 degrees to the horizontal and the rope is inclined at 50 degrees to the horizontal and it is the angle of inclination of the rope with respect to the ramp we require to get the work done by the rope in pulling the carton on the ramp
work done = 72 x 5.2 x cos 20
work done = 351.8 J
Answer:395.6 m/s
Explanation:
Given
mass of bullet 
mass of wood block 
Length of string 
Center of mass rises to an height of 
initial velocity of bullet 
let
and
be the velocity of bullet and block after collision
Conserving momentum
-------------1
Now after the collision block rises to an height of 0.38 cm
Conserving Energy for block
kinetic energy of block at bottom=Gain in Potential Energy




substitute the value of
in equation 1


Answer:
Please find the answer in the explanation
Explanation:
Given that A 1.0 g plastic bead, with a charge of -6.0 nC, is suspended between the two plates by the force of the electric field between them.
Since it is suspended, it must have been repelled by the bottom negative plate and trying to be attracted to the top plate.
We can therefore conclude that the upper plate, is positively charged
B.) The charge on the positive plate of parallel-plate capacitor is constructed of two horizontal 12.0-cm-diameter circular plates must be less than 6.0 nC
Answer:
The minutes hand travels 39.60 cm.
Explanation:
Note: a clock has a shape of a circle, the minutes hand is the radius, and the travel of the minutes hand forms a arc.
Length of an arc = ∅/360(2πr)
L = ∅/360(2πr).................... Equation 1π
Where L = length of an arc, ∅ = angle formed by an arc, r = radius of the arc.
Given: ∅ = 252°, r = 9 cm, π = 3.143.
Substituting these values into equation 1,
L = 252/360(2×3.143×9)
L = 0.7×2×3.143×9
L = 39.60 cm.
Thus the minutes hand travels 39.60 cm.
Answer:
B.
Explanation:
One of the ways to address this issue is through the options given by the statement. The concepts related to the continuity equation and the Bernoulli equation.
Through these two equations it is possible to observe the behavior of the fluid, specifically the velocity at a constant height.
By definition the equation of continuity is,

In the problem
is
, then


<em>Here we can conclude that by means of the continuity when increasing the Area, a decrease will be obtained - in the diminished times in the area - in the speed.</em>
For the particular case of Bernoulli we have to


For the previous definition we can now replace,


<em>Expressed from Bernoulli's equation we can identify that the greater the change that exists in pressure, fluid velocity will tend to decrease</em>
The correct answer is B: "If we increase A2 then by the continuity equation the speed of the fluid should decrease. Bernoulli's equation then shows that if the velocity of the fluid decreases (at constant height conditions) then the pressure of the fluid should increase"