(a)A light-rail commuter train accelerates at a rate of 1.45 m/s2. How long (in s) does it take to reach its top speed of 80.0 km/h, starting from rest?
s
(b)The same train ordinarily decelerates at a rate of 1.95 m/s2. How long (in s) does it take to come to a stop from its top speed?
s
(c)In emergencies the train can decelerate more rapidly, coming to rest from 80.0 km/h in 8.30 s. What is its emergency deceleration in m/s2?
m/s2
In: Physics
Titan’s atmosphere contains a large amount of photosensitive methane. We knowbecause of basic physics and chemistry that there must be a source of methane onTitan that replenishes the atmospheric methane.
a) Describe what astronomers thought might be occurring on Titan before the Cassini/Huygensmission.
b) Describe the findings of the Cassini/Huygens mission that either supported or dis-proved the original hypotheses
In: Physics
1. on a warm day, a tube open on one end resonates at 51.3 cm and 85.8 cm when the subject to 500 Hz input. what is the velocity of sound at that moment, and what is the correction value of the tube?.
2. you are driving down the highway at 35 m/s when an ambulance comes up behind you, and then passes (you illegally do not slow down). The passenger in the seat next to you has perfect pitch and tells you that the apparent frequency of the ambulance dropped by 2.0% when the ambulance passed. How fast was the ambulance traveling? (Assume a speed of sound is 341 m/s)
In: Physics
A ladder of mass 30 kg and length 5m leans against a frictionless wall. The angle between the ladder and the wall is 37 degree. (a) what is the force between the ladder and the wall? (b) a 60 kg man now climbs up to the midpoint of the ladder, what is the force at the base of the ladder (magnitude and direction).? (c) what must be the coefficient of friction so that the mass can climb all the way to the top of the ladder without slipping?
In: Physics
Ball 1, with a mass of 110 g and traveling at 15 m/s , collides head on with ball 2, which has a mass of 340 g and is initially at rest.
What is the final velocity of the ball 1 if the collision is perfectly elastic?
What is the final velocity of the ball 2 if the collision is perfectly elastic?
What is the final velocity of the ball 1 if the collision is perfectly inelastic?
What is the final velocity of the ball 2 if the collision is perfectly inelastic?
In: Physics
(a)Two charges are placed on the x-axis: one is placed at x = 3 m and the other is at x = -3 m. The magnitude of both charges is 9.7
In: Physics
n = 2.94 mol of Hydrogen gas is initially at T = 381 K temperature and pi = 2.24×105 Pa pressure. The gas is then reversibly and isothermally compressed until its pressure reaches pf = 7.63×105 Pa. What is the volume of the gas at the end of the compression process?
*****What would be the temperature of the gas, if the gas was allowed to adiabatically expand back to its original pressure?
In: Physics
A:What must be the density of the oil?
B:If the vehicle is taken to Mars, where the acceleration due to gravity is 0.379 g, what will be the pressure difference (in earth atmospheres) between the top and bottom of the oil column?
In: Physics
What is exponential growth? What consequences can we expect if U.S. population growth and energy consumption continue to grow exponentially? What are renewable energy sources and how can using renewable energy to generate electricity help alleviate this problem?
In: Physics
Charges of the amount 45 nC/m (charge per length) are deposited at the surface of a long, straight metal wire of diameter = 2 mm in which the surrounding media is air.
(a) Which electric field and potential distribution exists
around the wire ?
(b) How large is the electric field and the surface charge density
at the wire's surface ?
In: Physics
In a downhill ski race surprisingly little advantage is gained by getting a running start. This is because the initial kinetic energy is small compared with the gain in gravitational potential energy even on small hills. To demonstrate this, find the final speed and the time taken for a skier who skies 75.0 m along a 25
In: Physics
In: Physics
Calculate the mass of the sun from the radius of the earth's orbit (1.50×1011 m), the earth's period in its orbit, and the gravitational constant G.
What is the density of the sun ? (The sun's radius is 6.96×108 m). Notice how it compares with the density of the earth.
In: Physics
An isolated charged conducting sphere has a radius R = 14.0 cm. At a distance of r = 24.0 cm from the center of the sphere the electric field due to the sphere has a magnitude of E = 4.90 ✕ 104 N/C. (a) What is its surface charge density (in µC/m2)? µC/m2 (b) What is its capacitance (in pF)? pF (c) What If? A larger sphere of radius 30.0 cm is now added so as to be concentric with the first sphere. What is the capacitance (in pF) of the two-sphere system? pF
In: Physics
1)suppose we start with an electron with zero initial velocity. Let ϝ be
the typical time it would take for our electron to hit an atom. We can use this as
an average time between collisions as the electron makes its way through the
material. What is the typical velocity of the electron when it hits an atom?
2) It turns out that the velocity you just calculated is not a bad estimate of the drift
velocity, vd. Now, as we saw, there is another way to write vd, namely
J = (❝ne)vd for electrons (remember J = i / A for uniform current density), where
n is the number of charge carriers (electrons) per unit volume. Solve this for |vd|
and equate with what you got in (1).
3)In the above, you should have a J on one
side and an E on the other. Now J and E
are in another important equation from today. Given that, can you
find an
expression for the resistivity of the material, ??
4)Also, we just saw in lecture that R =
(L/A)?, where L is the length of the wire and
A is its cross-sectional area. So, what
In: Physics