HELP ME GUYS ITS A TEST GRADEEEEE PLSS
1 answer:
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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:
The time is 2.8 ms.
Explanation:
Given that,
Capacitor = 0.12 μF
Resistance = 10 kohm
Voltage = 12 V
Charge Q = 0.9 Q₀
We need to calculate the time constant
Using formula of time constant
Put the value into the formula
We need to calculate the time
Using formula of time
Put the value into the formula
Hence, The time is 2.8 ms.
Answer:
Work done is 1.31 J.
Explanation:
Given:
Length of the ramp (L) = 5.0 mm
Height of the top end (H) = 1.4 mm
Horizontal force applied (F) = 270 N
Work done (W) = ?
We know that,
Work done is equal to the product of force and displacement caused along the line of application of force.
Here, the force acting on the refrigerator is in the horizontal direction while the refrigerator is moving down along the length of the ramp. So, we have to first find the horizontal component of the displacement caused.
Now, consider the triangle ABC representing the given situation. The point A is the top end point of the ramp, AB is the length of the ramp, AC is the vertical displacement of the refrigerator and BC is the horizontal displacement of the refrigerator.
Using Pythagoras theorem,
Now, force applied on the refrigerator is in the direction opposite to the horizontal component of displacement. So, work is negative.
Work = Force × Horizontal displacement
Therefore, work done is 1.31 J.
