I am modeling HO (1:87) scale trains. A scale mile is approximately 60.68 feet. How long, in real time, should the model take to traverse this distance to cover the distance at a scale 10 MPH, or 30 MPH, and so on. I know there has to be a simple formula for making these calculations, but, I really didn’t pay much attention in math class. Help me out here, please.
Posted in Model Trains
Tagged anyone, attention, distance, formula, HO, math class, mile, modeling, mph, real time, scale, scale mile, scale trains, time, traverse
1. A worker pulls a sled with a force of 80 N directed at an angle of 60 degrees above the horizontal over a level distance of 6 m. If a frictional force of 24 N acts on the sled in a direction opposite to that of the worker, what net work is done on the sled?
a. 240 J, b. 216 J, c. 144 J, d. 96 J
2. A model rocket sits on the launch pad until its fuel is ignited, blasting the rocket upward. During the short time of blast-off, as the ignited fuel goes down, the rocket goes up because:
a. momentum is conserved in this process
b. the fuel pushes on the ground
c. air friction pushes on the escaping fuel
d. the downward force of gravity is less than the downward momentum of the fuel
please explain why you believe the answers are what they are just in case yours are different than mine. thanks a lot guys!
3. A 10 g bullet with an initial speed of 100 m/s is fired horizontally into a 90 g wodden block initially at rest on a frictionless horizontal surface. The bullet passes completely through the block and emerges with a final speed of 20 m/s in the horizontal direction. How much mechanical energy is lost in this process?
a. 44.4 J
b. 50 J
c. 26.4 J
d. 20 J
Posted in Model Rockets
Tagged acts, angle, direction, distance, Force, frictional, frictional force, horizontal, level, sled, work, worker
1. A worker pulls a sled with a force of 80 N directed at an angle of 60 degrees above the horizontal over a level distance of 6 m. If a frictional force of 24 N acts on the sled in a direction opposite to that of the worker, what net work is done on the sled?
a. 240 J, b. 216 J, c. 144 J, d. 96 J
2. A model rocket sits on the launch pad until its fuel is ignited, blasting the rocket upward. During the short time of blast-off, as the ignited fuel goes down, the rocket goes up because:
a. momentum is conserved in this process
b. the fuel pushes on the ground
c. air friction pushes on the escaping fuel
d. the downward force of gravity is less than the downward momentum of the fuel
please explain why you believe the answers are what they are just in case yours are different than mine. thanks a lot guys!
3. A 10 g bullet with an initial speed of 100 m/s is fired horizontally into a 90 g wodden block initially at rest on a frictionless horizontal surface. The bullet passes completely through the block and emerges with a final speed of 20 m/s in the horizontal direction. How much mechanical energy is lost in this process?
a. 44.4 J
b. 50 J
c. 26.4 J
d. 20 J
Posted in Model Rockets
Tagged acts, angle, check, direction, distance, Force, frictional, frictional force, horizontal, level, physics, physics problems, sled, worker
hi guys was just wandering i am new to RC flying i have a chopper my self and was wandering on the transmitter it has its “chip” of 35 MHz what does this have to do with it? the distance before it loses signal or something else?
Posted in RC Helicopter
Tagged chip, chopper, distance, Mhz, self, signal, something, transmitter
The best 3 channel mini rc helicopter for only £18.99 including postage! this heli has a bigger battery and a metal airframe even with bearings on the rotor shaft. the detail is brilliant and it also flies very well. i have had many mini rc heli’s and this one is the best by far. it comes with spare blades and a screwdriver. i would recommend using rechargeable batteries as the heli charges from the transmitter and eats batteries as you will be addicted to this heli. it is very stable and easy to control with left, right, forwards and backwards control. The heli comes in three colours, red, green and yellow. i am still amazed at the price for this heli as it is very well built, does not look cheap and flies brilliantly. a 25 minute charge gives roughly 5-9 minutes of flight time. Enjoy and please leave a comment.
Posted in RC Helicopter
Tagged 3-Channel, 3ch, airframe, airoplane, Airplane, best, channel, control, Controlled, distance, Electric, ga, heli, Helicopter, hobby, ic, infrared, karaoke, lady, londen, Metal, Micro, mini, Radio, RADIOCOMMANDE, RC, remote, S010, smallest, syma, Technical, three, Toegevoegd, toys, vision, VOIES, x-power
I need a cheap Radar Gun that measures a long distance between yourself and the boat. where can i purchase one? i have looked all over the net and seen many for $800 to $1000 which is too much considering what i need it for. i also seen the Hot Wheels radar gun but it only measures a short distance.. Im running a 1/8th Hydroplane Rc Boat. i have just rebuilt it , after it caught a pocket of air on the last run and flew a few meters in the air before coming down ripping it apart in some areas. now i want to know what speed i was travelling at for it to cause the damge. if anyone can help be great!
Cheers!
Posted in RC Boats
Tagged air, australia, boat, distance, gun, Hot, hot wheels radar gun, hydroplane, long distance, pocket, radar, rc boat, speed, wheels
A lightning bug flies at a velocity of 0.25 m/s due east toward another lightning bug seen off in the distance. A light easterly breeze blows on the bug at a velocity of 0.25 m/s. What is the resultant velocity of the lightning bug?
0.00 m/s
0.25 m/s East
0.25 m/s West
0.5 m/s East
A jogger runs 10.0 blocks due east, 5.0 blocks due south, and another 2.0 blocks due east. Assume all blocks are of equal size. What is the magnitude of the jogger’s net displacement?
7.0 blocks
12.0 blocks
13.0 blocks
17.0 blocks
An airplane flying at 120 km/h due west moves into a region where the wind is blowing at 40 km/h due east. If the plane’s original vector velocity is Vplane, what is the expression for the plane’s resulting velocity in terms of Vplane?
Vplane
Vplane
1 Vplane
80 Vplane
A quarterback takes the ball from the line of scrimmage and runs backward for 10 m. He then runs sideways, parallel to the line of scrimmage for 15 m. Next, he throws the ball forward 50 m, perpendicular to the line of scrimmage. The receiver is tackled immediately. How far is the football displaced from its original position?
43 m
225 m
1,600 m
1,825 m
A duck waddles 2.5 m east and 6.0 m north. What are the magnitude and direction of the duck’s displacement with respect to its original position?
6.0 m at 50° north of east
42.25 m at 67° north of east
6.5 m at 23° north of east
6.5 m at 67° north of east
A fox sees a piece of carrion being thrown from a hawk’s nest and rushes to snatch it. The nest is 14.0 m high, and the carrion is thrown with a horizontal velocity of 1.5 m/s. The fox is 7.0 m from the base of the tree. What is the magnitude of the fox’s average velocity if it grabs the carrion in its mouth just as it touches the ground?
(Assume no air resistance and that ay = g = 9.81 m/s2.)
1.7 m/s
3.5 m/s
4.2 m/s
2.6 m/s
A cat pushes a ball from a 7.00 m high window, giving it a horizontal velocity of 0.20 m/s. How far from the base of the building does the ball land? (Assume no air resistance and that ay = g = 9.81 m/s2.)
0.24 m
1.4 m
7.0 m
7.2 m
A model rocket flies horizontally off the edge of a cliff at a velocity of 50.0 m/s. If the canyon below is 100.0 m deep, how far from the edge of the cliff does the model rocket land? (Assume no air resistance and that ay = g = 9.81 m/s2.)
226 m
245 m
350 m
526 m
A boat moves at 10.00 m/s relative to the water. If the boat is in a river where the current is 2.00 m/s, how long does it take the boat to make a complete round trip of 1,000.0 m upstream followed by 1,000.0 m downstream?
83 s
125 s
200 s
208 s
A person is strolling along a moving walkway at a constant velocity of +1.00 m/s with respect to the walkway, which moves at a constant velocity of +0.50 m/s with respect to the ground. An observer on the ground is walking at a constant velocity of -0.2 m/s. What is the velocity of the person on the walkway with respect to the observer on the ground?
– 0.7 m/s
+ 1.3 m/s
– 0.3 m/s
+ 1.7 m/s
Posted in Model Rockets
Tagged breeze, breeze blows, bug, distance, due east, Light, Lightning, lightning bug, physics, resultant velocity, someone, velocity
