The amswer should be B. reduce the mass
The frequency of a wave is 2 Hz and the wavelength is 4 m. What is the wave speed?
Answer:
4/2=2m/s
Explanation:
What is another name for constructive interference?
A. Up
B. Down
C. Reinforcement
D. Cancellation
A 1500 kg car accelerats from 55.0 m/s to 90.0 m/s. Calculate the impulse experienced by the car
Answer:
The impulse experienced by the car is 52,500 kg.m/s.
Explanation:
Given;
mass of the car, m = 1500 kg
initial velocity of the car, u = 55 m/s
final velocity of the car, v = 90 m/s
The impulse experienced by the car is the change in linear momentum, calculated as follows;
J = ΔP = mv - mu
ΔP = m(v - u)
ΔP = 1500(90 - 55)
ΔP = 52,500 kg.m/s
Therefore, the impulse experienced by the car is 52,500 kg.m/s.
A fall thrown vertically upwards with a speed
of 20 ms-¹ from the top of a tower reaches
the earth in 8seconds. find the height of the
tower.
take g= 10ms-²
Answer:
Height of tower = 480 meter
Explanation:
Given:
Initial velocity = 20 m/s
Time taken to reach ground = 8 second
So,
Final velocity = 0 m/s
Acceleration due to gravity = 10 m/s²
Find:
Height of tower
Computation:
s = ut + (1/2)(g)(t)²
s = (20)(8) + (1/2)(10)(8)²
s = 160 + (1/2)(10)(64)
s = 160 + (10)(32)
s = 160 + 320
s = 480 meter
Height of tower = 480 meter
A 140 g tennis ball travelling 30° east of north at 15 m/s is struck by a tennis racquet, giving it a velocity of 25 m/s, west. What are the magnitude and direction of the impulse given to the ball? Include a labelled diagram.
Answer:
The magnitude of the impulse is 1.4 Ns in the West direction.
Explanation:
The impulse equation is given by:
[tex]\Delta p=m\Delta v[/tex]
Where:
m is the mass of the ballΔv is the difference in velocitySo we will have:
[tex]\Delta p=0.140(25-15)[/tex]
[tex]\Delta p=1.4\: Ns[/tex]
Therefore, the magnitude of the impulse is 1.4 Ns in the West direction.
I hope it helps you!
Which of the following is evidence that a chemical reaction has occurred?
Dr. Kirwan is preparing a slide show that he will present to the executive board at tonight's committee meeting. He places a 3.50-cm slide behind a lens of 20.0 cm focal length in the slide projector. A) How far from the lens should the slide be placed in order to shine on a screen 6.00 m away? B) How wide must the screen be to accommodate the projected image?
Answer:
A) d_o = 20.7 cm
B) h_i = 1.014 m
Explanation:
A) To solve this, we will use the lens equation formula;
1/f = 1/d_o + 1/d_i
Where;
f is focal Length = 20 cm = 0.2
d_o is object distance
d_i is image distance = 6m
1/0.2 = 1/d_o + 1/6
1/d_o = 1/0.2 - 1/6
1/d_o = 4.8333
d_o = 1/4.8333
d_o = 0.207 m
d_o = 20.7 cm
B) to solve this, we will use the magnification equation;
M = h_i/h_o = d_i/d_o
Where;
h_o = 3.5 cm = 0.035 m
d_i = 6 m
d_o = 20.7 cm = 0.207 m
Thus;
h_i = (6/0.207) × 0.035
h_i = 1.014 m
What will happen to the force felt between two charged objects if the distance between them is 1/3rd of the original distance
Answer:
New force = 9(initial force)
Explanation:
The force between two charges is given by :
[tex]F=\dfrac{kq_1q_2}{r^2}[/tex]
Where
d is the original distance
Let d' is the new distance such that, r' = r/3
New force,
[tex]F'=\dfrac{kq_1q_2}{r'^2}\\\\F'=\dfrac{kq_1q_2}{(\dfrac{r}{3})^2}\\\\F'=9\times \dfrac{kq_1q_2}{r^2}\\\\F'=9F[/tex]
So, the new force becomes 9 times the initial force.
Which is closest to the Earth?
A. Moon
B. Sun
C. Mars
D. Venus
Answer:
A. Moon
Explanation:
The Moon is hundreds of thousands of miles away from the Earth while the other options are hundreds of millions of miles away.
How are frequency, wavelength, and energy related? Choose all that apply.
Explanation:
The energy of a wave is given by :
[tex]E=\dfrac{hc}{\lambda}[/tex]
Where
h is Planck's constant
c is the speed of light
[tex]\lambda[/tex] is wavelength
Energy is inversely proportional to wavelength. Also, the relation between frequency and wavelength is inverse.
If the frequency is high, the wavelength will be shorter.
Hence, the correct options are :
Higher frequencies have shorter wavelengths.
Shorter wavelengths have lower energy.
Lower frequencies have lower energy.
What is the highest Mountain, and where is it?
Answer:
Mount Everest is Earth's highest mountain above sea level, located in the Mahalangur Himal sub-range of the Himalayas. The China–Nepal border runs across its summit point. Its elevation of 8,848.86 m was most recently established in 2020 by the Nepali and Chinese authorities.
Explanation:
Our entire ______ _____
is built in the backbone of metals.
Answer:
modern world
Explanation:
