An 8 m long uniform plank of mass 140 kg rests on the side of a pirate ship with 3 meters extended over the edge. How far can a 60 kg prisoner venture past the odge of the ship on the plank before the plank just begins to tip? Please select the correct answer from the choices shown below: A. 1,5 m B. 1.67 m C. 2 m D. 2.33 m Reset Selection
The energy applied to cause vibration can be in the form of air pressure, a stick,a bow, or electricity. A. False B. True
What do.scientists know about the future of the universe? what dark matter is made of why the expansion of the universe is accelerating that stars will eventually burn out causing the universe to become cold and dark that galaxies spin much slower than they should based on visible matter
10. Which of these illustrates how air resistance can change an object's falling speed? A. An astronaut floating in space B. A coin dropped from a building C. A parachute slowing a skydiver D. A boulder rolling off a cliff
What is the center of an atom called? electron cloud proton center photon center nucleus
The first energy shell contains a maximum of __ electrons. Select one: a. 1 b. 2 C. 4 d. 8
4x The statement can be made that atoms and molecules are always in motion. Formulate a reason that solids can exist. A The internal energy of the atoms is not enough to allow the atoms to disassociate from its neighbors. B External energy output is strong enough to allow the atoms to withdraw from its nearest neighbors. C Intermolecular forces are inadequate to allow the atoms to break away from its nearest neighbors. D Activation energy is equivalent to allow the atoms to migrate away from its nearest neighbors.
What does a negative velocity indicate? The object is moving backwards The object is speeding up The object is at rest The object is slowing down
What is the speed of sound in air that students need to remember? 550 meters per second 330 meters per second 250 meters per second 1000 meters per second
How does the speed of sound waves change in different mediums? It only changes in water It only changes in air It remains constant It varies depending on the medium
\#4) A mass of 4 kg stretches spring 40 cm. The mass is acted on by an external force of $180e^{-2t}+196N$ and moves in a medium that imparts a viscous force of 34 N when the speed of the mass is $\frac {1}{3}m/sec$ Mass is set in motion from equilibrium position with an initial velocity of $1m/sec$ A) Formulate an initial value problem $(IVP)$ B) Solve the IVP
When a stone is dropped in a pond ripples are formed and travel in concentric circles away from where the stone. was dropped. The equation of the least-squares regression line is $\hat {Area}=0.010+3.141(Time^{2})$ What is the predicted area, in $cm^{2}$ of the circle 8 seconds after the stone was dropped? $25.14cm^{2}$ $50.27cm^{2}$ $64.01cm^{2}$ $201.03cm^{2}$
Caleb is investigating the effect of friction on the motion of an object. He uses the following supplies for the investigation: a wooden block three ramps, each ramp is the same height and length but has a different surface (smooth wood, carpet rough sandpaper) a stopwatch
All the following are correct,except: The law of conservation of energy states that energy can never be created or destroyed. When food is cooked on a stove. some of the thermal energy from the burner transfers to the surrounding air. During the transfer of thermal energy, no energy is gained or lost. Energy cannot change form
For a given process a system emits 322kJ of heat at the same as it performs 22 kJ of work The values of $\Delta H$ and $\Delta E$ respectively are 322kJ and 344kJ $-322kJ$ and $-344kJ$ $-344kJ$ and $-322kJ$ 344kJ and 322kJ
How long (in seconds)must a de-orbit burn last if the rocket is 25,848kg and a rocket force of 53,000 newtons to go from 334.8 km to 96.5 km if the mass does not change
In a dam, water flows through a(n) __ to make electricity. wire generator battery Rewatch
5. (5 marks) A circular cylinder of radius $R=5$ m and height $H=10m$ half full of water.Using the density of water $\rho =1000kg/m^{3}$ and earth's gravitational constant $g=9.8N/kg$ calculate the work done in pumping all the water out the top. State your answer in scientific notation with two signficant figures, e.g. $1.4\times 10^{5}$ and with correct units. $\square $
9. Even though outer space has a temperature near zero Kelvin (absolute zero or about $-273^{\circ }C)$ water would exist only as a gas, and not a solid. Explain this phenomena in terms of air pressure and boiling points. 10. Would it take longer to cook a pot of pasta in Denver, Colorado, or Lincoln Nebraska?
36. A box falls off a warehouse shelf from a height of 64 feet. The function $h(t)=-16t^{2}+64$ represents the h, height in feet, after t seconds. How long does it take the box to hit the ground?
