Relative humidity isn't everything. Why is it that outdoor air of 80 Fo at 55% humidity will feel more “muggy” than a 50 Fo cave at 75% humidity? What other parameter is a better measure of the actual amount of moisture in the air, and how do we define it? Then give two examples of when keeping close track of moisture in the air is important.

1. A ball of negligible size and a given mass is attached to a vertical spring that obeys Hooke's law. The mass is set in oscillation in a vertical direction. At equilibrium, its position is recorded to be "zero". At what point during the oscillation will the ball-earth-spring system have the maximum elastic potential energy?

6. In transverse waves...

A mass is moving at 10 m/s in the +x direction and it collides in a perfectly elastic collision with a mass of 4 kg moving in the -x direction. The collision takes places in 0.22 seconds and after the collision the mass that was moving in the +x direction is moving in the -x direction at 8 m/s and the mass that was moving in the -x direction is moving in the +x direction at 14 m/s. What is the magnitude of the average force, in Newtons, on the first mass which was originally moving in the +x direction before the collision?

Standard test conditions (STC) for panels are 1000 W/m²incoming radiation, panel oriented normal to the sun, and 25 °C.  If all other conditions are the same but we decrease the temperature, how will this affect power output of the panel, relative to its STC rating?  Why?

How is solar energy wasted when the frequency of incoming solar radiation is too low? When the frequency is too high?

How does a multi-junction solar cell improve efficiency compared to a single-junction cell?

Steam at 100 °C is bubbled into 2.70 kg of water at 25 °C in a calorimeter cup. How much steam will have been added when the water in the cup reaches 55 °C? (Ignore the effect of the cup.)​

What is the ideal mechanical advantage in using a (frictionless) ramp to raise a mass of 9 kg that is at an angle of theta θ = 22 degrees. Explanation needed please. Thank you..

What is the abjective, goal, abstract, and purpose of rotational kinetic energy lab in physics

Global warming has been linked to the growth of population of some insects and pests in cooler areas where they have not been previously seen. What global systems does this population growth affect? Identify a positive and a negative feedback resulting from it.

1) While standing on a stationary skateboard, Sunita catches a heavy ball thrown to her by a friend in the direction that the skateboard is pointing. What is the result of her catching the ball?

A. She begins rolling at the same speed the ball had before she caught it.

B. She begins rolling at a greater speed than the ball had before she caught it.

C. She begins rolling at a lower speed than the ball had before she caught it.

D. She remains stationary after catching the ball.

2)A figure skater performing a spin starts with his arms spread wide and then brings them in close to his body. What is the result?

A. His angular velocity increases, since his moment of inertia decreased.

B. His angular velocity increases, since his moment of inertia increased.

C. His angular velocity decreases, since his moment of inertia decreased.

D. His angular velocity decreases, since his moment of inertia increased.

As a city planner, you receive complaints from local residents about the safety of nearby roads and streets. One complaint concerns a stop sign at the corner of Pine Street and 1st Street. Residents complain that the speed limit in the area (55 mph) is too high to allow vehicles to stop in time. Under normal conditions this is not a problem, but when fog rolls in visibility can reduce to only 155 feet. Since fog is a common occurrence in this region, you decide to investigate. The state highway department states that the effective coefficient of friction between a rolling wheel and asphalt ranges between 0.536 and 0.599, whereas the effective coefficient of friction between a skidding (locked) wheel and asphalt ranges between 0.350 and 0.480. Vehicles of all types travel on the road, from small VW bugs weighing 1150 lb to large trucks weighing 7440 lb. Considering that some drivers will brake properly when slowing down and others will skid to stop, calculate the miminim and maximum braking distance needed to ensure that all vehicles traveling at the posted speed limit can stop before reaching the intersection.

A uniform ladder stands on a rough floor and rests against a frictionless wall as shown in the figure. 2 58 1 Since the floor is rough, it exerts both a normal force N1 and a frictional force f1 on the ladder. However, since the wall is frictionless, it exerts only a normal force N2 on the ladder. The ladder has a length of L = 4.5 m, a weight of WL = 63.5 N, and rests against the wall a distance d = 3.75 m above the floor. If a person with a mass of m = 90 kg is standing on the ladder, determine the following.

(a) the forces exerted on the ladder when the person is halfway up the ladder (Enter the magnitude only.)

N1 = ____ N

N2 = ____ N

f1 = ____ N

(b) the forces exerted on the ladder when the person is three-fourths of the way up the ladder (Enter the magnitude only.)

N1 = ____ N

N2 = ____ N

f1 = ____ N

An green hoop with mass m_h = 2.8 kg and radius R_h = 0.12 m hangs from a string that goes over a blue solid disk pulley with mass m_d = 1.9 kg and radius R_d = 0.09 m. The other end of the string is attached to a massless axel through the center of an orange sphere on a flat horizontal surface that rolls without slipping and has mass m_s = 3.8 kg and radius R_s= 0.22 m. The system is released from rest.

What is magnitude of the linear acceleration of the hoop?

What is magnitude of the linear acceleration of the sphere? '

What is the magnitude of the angular acceleration of the disk pulley?

What is the magnitude of the angular acceleration of the sphere?

What is the tension in the string between the sphere and disk pulley?

What is the tension in the string between the hoop and disk pulley?

The green hoop falls a distance d = 1.69 m. (After being released from rest.) How much time does the hoop take to fall 1.69 m?

What is the magnitude of the velocity of the green hoop after it has dropped 1.69 m?

What is the magnitude of the final angular speed of the orange sphere (after the green hoop has fallen the 1.69 m)?

In the figure, a conducting rod of length L = 29.0 cm moves in a magnetic field B⃗ of magnitude 0.390 T directed into the plane of the figure. The rod moves with speed v = 6.00 m/s in the direction shown.

When the charges in the rod are in equilibrium, what is the magnitude E of the electric field within the rod?

What is the magnitude Vba of the potential difference between the ends of the rod?

What is the magnitude E of the motional emf induced in the rod?

Assume that the firework has a mass of m_0 = 0.30~\text{kg}m​0​​=0.30 kg and is launched from a cannon at an angle of \theta_0 = 41.8^\circθ​0​​=41.8​∘​​ with an initial velocity of | v_0 | = 20~\text{m/s}∣v​0​​∣=20 m/s. Just as the firework reaches its hight point in its trajectory, it explodes into two pieces. Immediately after the explosion, the first piece, with a mass of m_1 = 0.2~\text{kg}m​1​​=0.2 kg flies off at an angle \theta_1 = 150^\circθ​1​​=150​∘​​ relative to the positive (forward) horizontal axis at a velocity of | v_1 | = 5~\text{m/s}∣v​1​​∣=5 m/s relative to the ground. Calculate the trajectory angle, \theta_2θ​2​​ of the second piece immediately after the explosion. Assume the second piece has a mass of m_2 = 0.1~\text{kg}m​2​​=0.1 kg, neglect the effect of air resistance, and report your result as an angle relative to the positive (forward) horizontal axis.