Answer:
The stitches and dimples around a baseball and a golf ball respectively, disturbs the air drag on the balls once they are in motion, allowing the them to travel more easily.
Explanation:
The stitches on a baseball disturbs the air drag on the ball when the ball is in motion, allowing the ball to travel more easily. Depending on the orientation of the ball in flight, the drag changes as the flow is disturbed by the stitches.
A smooth ball with no stitches or dimples has more air drag that opposes the motion.
A golf ball is smooth ball with dimples to create a thin turbulent boundary layer of air that clings to the ball's surface. This allows the smoothly flowing air to follow the ball's surface a little farther around the back side of the ball, thereby decreasing the size of the wake, and allowing the ball to travel more easily.
Answer:
(a) T = 0.015 N
(b) M = 1.53 x 10⁻³ kg = 1.53 g
Explanation:
(a) T = 0.015 N
First, we will find the speed of waves:
where,
v = speed of wave = ?
f = frequency = 120 Hz
λ = wavelength = 6 cm = 0.06 m
Therefore,
v = (120 Hz)(0.06 m)
v = 7.2 m/s
Now, we will find the linear mass density of the coil:
where,
μ = linear mass density = ?
m = mass = 1.45 g = 1.45 x 10⁻³ kg
l = length = 5 m
Thereforre,
Now, for the tension we use the formula:
<u>T = 0.015 N</u>
<u></u>
(b)
The mass to be hung is:
<u>M = 1.53 x 10⁻³ kg = 1.53 g</u>
Answer:
0.7 hours
Explanation:
From the way back, we can calculate the distance between Irina's work and Irina's home. In fact, we know that the car takes 0.4 hourse traveling at 27 mph, so the distance covered should be
When Irina rides to work with her bike, she travels at a speed of 16 mph. So we can find the time she takes by dividing the total distance (10.8 miles) by her speed:
Answer:
The velocity of the freight car decreases.
Explanation:
This question is answered by the conservation of momentum principle.
When the freight car is moving at a certain speed, it has a constant momentum.
We will call this M1.
The equation for M1 will be:
M1 = Mass * Speed
Now when the coal is dumped into the freight car, the Mass increases.
Since conservation of momentum states that the momentum will remain the same. We have:
M1 = (Mass of freight + Mass of coal) * Speed
Since M1 is constant, if the mass increases, the speed had to decrease to keep the equation true.
Some benefits to solar power:
Isolated power is very abundant on earth.
Is very sustainable (5 billion years of good use)
Eco friendly excluding panel production.
Some disadvantages:
Very expensive to set up
Takes up a lot of space per person
Requires exotic materials to construct
Energy storage is difficult with solar cells compared to fossil fuels.
