you read about a rope and pulley machine that was able to produce equal amounts of output work and input work.was this a realistic example? why or why not?
No, it isn’t a realistic example.
This is an example of an ideal scenarios when we ignore frictional losses. But, in real life there are frictional losses and tension on the both sides of the pulley will be different. So, we cannot get output work is equal to input work. Hence, it is not a realistic example but ideal one.
Who were major innovators of the late nineteenth or early twentieth century? Choose all answers that are correct.
Alexander Graham Bell
Orville and Wilbur Wright
While discussing different types of pressure plate assemblies, Technician A says coil spring types do not require release levers. Technician B says Belleville-type pressure plates are not commonly used because they require excessive space in the bell housing. Who is correct? a) Technician A only
b) Technician B only
c) Both A and B
d) Neither A nor B
Neither A nor B is correct because while discussing different types of pressure plate assemblies, Technician A says coil spring types do not require release levers and it is not correct. Technician B says Belleville-type pressure plates are not commonly used because they require excessive space in the bell housing and it is also not correct.
It takes 105 j of work to move 2.7 c of charge from the negative plate to the positive plate of a parallel plate capacitor. what voltage difference exists between the plates?
A school bus takes 0.530 h to reach the school from your house. If the average velocity of the bus is 19.0 km/h to the east, what is the displacement?
Average velocity Vavg=19.0 km/s
The Formula for average velocity is given as
The route followed by a hiker consists of three displacement vectors A with arrow, B with arrow, and C with arrow. Vector A with arrow is along a measured trail and is 1230 m in a direction 36.0° north of east. Vector B with arrow is not along a measured trail, but the hiker uses a compass and knows that the direction is 41.0° east of south. Similarly, the direction of vector vector C is 37.0° north of west. The hiker ends up back where she started, so the resultant displacement is zero, or A with arrow + B with arrow + C with arrow = 0. Find the magnitudes of vector B with arrow and vector C with arrow
B= 5,655 m C= 5,890 m.
We are told that the hiker ended up back where she started, so the total displacement was 0.
As displacement is a vector, if the magnitude is 0, this means that their components, along any axis must be 0 too.
If we choose the W-E direction as our x axis (with origin in the start and end point of the travel), being the E direction the positive, and we do the same with the N-S direction (we make it our y axis, with N as positive), we can write the following:
Δx = Δy=0
Next, we sum all the components of A, B and C along x axis, based on the question premises, as follows:
Δx = 1,230 m* cos 36º + B*sin 41º - C*cos 37º =0 (1)
Δy = 1,230 m*sin 36º -B*cos 41º + C* sin 37º = 0
We have a system of 2 linear equations with 2 unknowns (B and C) which can be solved by any suitable method: substitution, sum and substraction, determinants, etc).
Using determinants, we find first the determinant of the unknowns, as follows:
Δ = sin 41º*sin 37º - (-(cos 37º)*(-cos 41º) = -0.208
Now we find the numerator in order to get the value of B, replacing the B column by the independent terms'column:
ΔB = -1230*cos 36º*sin 37º - (-1230*sin 36º*(-cos 37º) = -1,177
⇒ B = ΔB / Δ = -1,177/-0.208 = 5,655 m
Repeating the same process, we get the value for ΔC, as follows:
ΔC = -1230*sin 36º*sin 41º - (-1230*cos 36º*(-cos 41º)) = -1,225
⇒ C = ΔC / Δ = -1,225/-0.208 = 5,890 m
Changes that occur in the urinary system with aging include all of the following, EXCEPT a. a decline in the number of functional nephrons
b. a reduction in the GFR (glomerular filtration rate)
c. increased sensitivity to ADH
d. problems with the micturition reflex
e. loss of sphincter muscle tone
Answer: c. increased sensitivity to ADH
a. a decline in the number of functional nephrons: With aging the loss of nephron occurs that can be detected by the age related decrease in the glomerular filteration rate.
b. a reduction in the GFR (glomerular filtration rate): The GFR tend to decline in older age even though there is no disease. These people are required to check with the GFR in future.
d. problems with the micturition reflex: With aging people experience problem of bladder control. This leads to leakage or incontinence of urine or urinary retention that is inability to empty the bladder.
e. loss of sphincter muscle tone: With age the sphincter tone may diminish. This results in loss of control and storage capacity. The rectal muscles or sphincter muscles get loose which lead to passage of stool before reaching the washroom.
experiment was performed on a 2-kg block. Forces of 5, 10 and 15 Newtons respectively were applied to the block for 5 seconds. Describe the difference in acceleration between the three trials. A) The final accelerations will all be the same. B) The final acceleration will triple between the first and third trial. C) The final acceleration will be cut by 1/3 from the first to third trial. D) The final acceleration will increase ni
B) The final acceleration will triple between the first and third trial.
From the relationship (acceleration) = (force) / (mass) it follows that the acceleration is directly proportional to the force applied. During the second experiment the acceleration will double (as force doubles), and during the third it will be tripled compared to the first.
A ball rolls without slipping down a tilted plane, starting from rest. At the same time, a box starts from rest and slides down the same plane, although we will assume that there is no friction for the box (note that friction is what allows the ball to roll). Which arrives at the bottom first?
This is because the effect that the friction force have depends on the mass, the angle also have a great effect in the answer, but it seems it is not an option, what is worth noticing is that the mass doesn't have effect in the ball rolling given that the friction is only responsible of the rolling.
For more information on this visit
The box arrives first.
The ball and the box start from rest and start with the same gravitational potential energy. That potential energy is converted into kinetic energy.
The mass m cancels on both sides of the equation and is not important to the problem.
The difference between the box and the ball comes from rotational energy. Only the ball will gain rotational energy because the box is sliding and will not rotate. The potential energy of the ball will be converted into kinetic and rotational energy. This means the kinetic energy of the ball will be smaller than the kinetic energy of the box, hence the box will be faster.