PLEASE HELP MEEEEEE
Some physical evidence was obtained from a crime scene. For which of these pieces of evidence will forensic scientists conduct an identification test?
A.
a hair strand
B.
a black powder
C.
a glove
D.
bloodstains
Answer:
The correct option is D. bloodstains
16. Through which of the following mediums is the velocity of a sound wave the greatest?
A. Steel
B. Lend
Water
D. Air
A.) Steel.
steel travels 5,060 meters per second,
lead travels 1,402 meters per second,
water travels 1,439 meters per second,
and air depends on temperature.
A skier rides horizontally off of a 200 meter high cliff. If he lands 25 meters away from
the base of the cliff, how fast was he skiing as he went off the edge?
Answer:3.91
Explanation:
(03.07 MC)
A 660 kg car is travelling around a circular track of radius 55.0 m at 11.5 m/s.
Calculate the force and its direction that provides the centripetal force acting on the car to keep it
in the circular path. (3 points)
a) 24 N toward the center of the circle
b) 24 N along the line tangent to the circle
c) 1.587 E3 N along the line tangent to the circle
d) 1.587 E3 N toward the center of the circle
Answer: D) 1.587 E3 N toward the center of the circle
This is the same as saying 1.587*10^3 newtons, or we can say 1587 newtons
=================================================
Work Shown:
m = mass = 660 kilograms
v = velocity = 11.5 meters per second
r = radius of circle = 55.0 meters
-------------
F = centripetal force = inward pulling force toward center of circle
F = (m*v^2)/r
F = (660*11.5^2)/55
F = 1587
F = 1.587 * 10^3
F = 1.587 E 3
The "E 3" notation is what many calculators display scientific notation to be
The units for the force here are in newtons.
The force is pulling on the object toward the center of the circle, which helps keep the car on the circular path, rather than it going off on a tangent.
1. What is the gravitational force of attraction between two 800 kg spherical objects that are 5 m apart? What would the gravitational force of attraction between these two objects be if the distance between them was changed to 10 m?
Answer:
the force of gravity between them is quadrupled .
Explanation:
Since gravitational force is inversely proportional to the square of the separation distance between the two interacting objects, more separation distance will result in weaker gravitational forces.
A wave vibrates up and down 22 cycles in 7 seconds with a wave speed of 57. Calculate the
wavelength. (Round to the 2nd number after the decimal)
Answer:
18.14m
Explanation:
Given parameters:
Frequency = [tex]\frac{22}{7}[/tex]cycles/s
Speed of wave = 57m/s
Unknown:
Wavelength = ?
Solution:
The speed of a wave is related to frequency and wavelength using the expression below;
V = f x λ
V is the speed of the wave
f is the frequency
λ is the wavelength
Insert the parameters and find λ;
57 = [tex]\frac{22}{7}[/tex] x λ
λ = 57 x [tex]\frac{7}{22}[/tex] = 18.14m
A force of 30 Newtons is used to push a basket along the floor a total distance of 3 meters. How much work is done on the basket?
Answer:
the total work done is 90J
Explanation:
the reason why is because you are the force (30 newtons) and the metere (3) so you will be multiplying those two numbers together.
W= FD 30(3)= 90J
A person walks 8 m/s towards the north. Is this an example of speed or velocity? Explain your answer.
Answer:
I think it is velocity.
because velocity shows the direction and magnitude .
Answer:
Velocity
Explanation:
This is a case of velocity, since velocity apart from having magnitude also has direction. the person walks at 8 [m/s] to the North.
When we talk about speed, we only talk about the magnitude without taking into account the direction.
The unit of the electric resistance is ???
Answer:
OhmsStep-by-step-explanation :
Electric resistance
Dimension length :
Squared mass per time cubed , that is , electric current squared.
The SI derived unit of electric resistance is the ohm,(volt per ampere).
An object travels in a straight line for 1200 m at a velocity of 50 m/s, what is its time of travel?
Given that,
distance = d = 1200m
velocity/speed = s = 50m/s
time = t
Also,
s = d/t
And,
t = d/s
t = 1200/50
t = 120/5
t = 24
Therefore, it takes 24s to travel.
Answer: Therefore, the travel time of a car that travels 1200 meters at 50 m/s is 24 seconds.
Explanation:
An object travels in a straight line for 1200 m at a velocity of 50 m/s, what is its time of travel?
Data:
d = 1200 m
V = 50 m/s
t = ?
The formula for uniform motion is:
V = d/tWhere
V = speedd = distancet = timeWe clear the formula for time t:
t = d/v
t = (1200 m)/(50 m/s)
t = 24 s
Therefore, the travel time of a car that travels 1200 meters at 50 m/s is 24 seconds.
The free-body diagram below shows the forces acting on a bicycle as the
rider pedals to the right. The vectors are not drawn to scale. The bicycle has a
weight of 700 N and a pedaling force of 325 N. As it moves, it encounters 100
N of air resistance. What is the net force on the bicycle in the x-direction?
Answer:
225 N to the right
Explanation:
got it wrong on the quiz and revealed the correct answer
Dose the atoms in a solid move freely or remain in a fixed position ?
- A type of elevator called a cage is used to raise and lower miners in a mine
shaft. Suppose the cage carries a group of miners down the shaft. If the
unbalanced force on the cage is 60.0 N, and the mass of the loaded cage is
1.50 10 kg, what is the acceleration of the cage?
Only visibly rough surfaces have friction between them
The car's initial speed was 15 m / s and the distance the car travels before it comes to a complete stop after the driver applies the brakes is 63m. What is the magnitude of the car's acceleration?
Initial speed of the car (u) = 15 m/s
Final speed of the car (v) = 0 m/s (Car comes to a complete stop after driver applies the brake)
Distance travelled by the car before it comes to halt (s) = 63 m
By using equation of motion, we get:
[tex] \bf \longrightarrow {v}^{2} = {u}^{2} + 2as \\ \\ \rm \longrightarrow {0}^{2} = {15}^{2} + 2 \times a \times 63 \\ \\ \rm \longrightarrow 0 = 225 + 126a \\ \\ \rm \longrightarrow 126a = - 225 \\ \\ \rm \longrightarrow a = - \dfrac{225}{126} \\ \\ \rm \longrightarrow a = - 1.78 \: m {s}^{ - 2} [/tex]
[tex] \therefore [/tex] Acceleration of the car (a) = -1.78 m/s²
Magnitude of the car's acceleration (|a|) = 1.78 m/s²
Which of the following games below involves different manipulative skills like throwing and rolling and some motor skills?
Group of answer choices
target games
invasion games
striking and fielding games
physical activity
Answer:
striking and fielding
Explanation:
striking and fielding
How should the student change the circuit to give negative values for current and
potential difference?
Answer:
changing the polarity or direction of the battery changes the sign of the voltage and the current
Explanation:
The sign of current and voltage are due to established conventions.
The way that a DC circuit with negative current values is by changing the polarity of the power source or by inverting the battery, this creates that the electrons move in the opposite direction
Changing the battery also changes the direction of the power difference, since the potential from positive to negative, in most cases negative is assigned a potential of zero volts
In summary, changing the polarity or direction of the battery changes the sign of the voltage and the current
How much time is required for a 20 Coulombs charge to flow through a point if the current is 2 amperes? help plzzzzz
The time required for a 20 coulombs charge to flow through a point if the current is 2 amperes will be 10 seconds.
What is electric current?Electric current is defined as the ratio of the charge flow in a given time interval. It is denoted by I. It has the unit is ampere.
The given data in the problem is;
t is the time is required
q is the charge = 20 Coulombs
I is the current is= 2 amperes
The formulas for the elctric current are given as;
[tex]\rm I = \frac{q}{t} \\\\\ \rm t = \frac{q}{I} \\\\ \rm t = \frac{20}{2} \\\\ t=10 \ sec[/tex]
Hence the time required for a 20 coulombs charge to flow through a point if the current is 2 amperes will be 10 seconds.
To learn more about the electric current refer to the link;
https://brainly.com/question/2264542
The time required for a 20 coulombs charge to flow through a point if the current is 2 amperes will be 10 seconds.
What is electric current?Electric current is defined as the ratio of the charge flow in a given time interval. It is denoted by I. It has the unit is ampere.
The given data in the problem is;
t is the time is required
q is the charge = 20 Coulombs
I is the current is= 2 amperes
The formulas for the electric current are given as;
[tex]I=\dfrac{q}{t}[/tex]
[tex]t=\dfrac{q}{I}[/tex]
[tex]t=\dfrac{20}{2}[/tex]
[tex]t=10 sec[/tex]
Hence the time required for a 20 coulombs charge to flow through a point if the current is 2 amperes will be 10 seconds.
To learn more about the electric current refer to the link;
brainly.com/question/2264542
A machine has mechanical advantage 2,what does it mean?
Answer:
The mechanical advantage of a machine is 2. Mechanical advantage MA is the ratio of output (generated by the machine) force to input (applied to the machine) force. So MA = 2 means that for example if you apply 100 N then your machine will multiply that force and generate 200 N .
Rohith has been jogging to the bus stop for 2.0 minutes at 3.5 m/s when he looks at
his watch and sees that he has plenty of time before the bus arrives. Over the next
10.0s, he slows his pace to a leisurely 0.75 m/s. What was his average acceleration
during this 10.0 s?
Function of nucleus
Answer:
The nucleus has very important roles to play. As it contains genetic material, it coordinates cell activities like protein synthesis and cell division.
Explanation:
A paintball is fired horizontally from a tower 45 m above the ground. If the paintball gun fires at 90 m/s… How long does it take for the paintball to hit the ground? How far away from the tower will the paintball land?
Answer:
The time taken for the paint ball to hit the ground is [tex]t = 2.143 \ s[/tex]
The distance of the landing point from the tower is [tex]d = 192.86 \ m[/tex]
Explanation:
From the question we are told that
The height of the tower is [tex]h = 45 \ m[/tex]
The speed of the paintball in the horizontal direction is [tex]v_x = 90 \ m/s[/tex]
Generally from kinematic equation we have that
[tex]h = ut + \frac{1}{2} at^2[/tex]
Here u is the initial velocity of the paintball in the vertical direction and the value is 0 m/s , this because the ball was fired horizontally
a is equivalent to [tex]g = 9.8\ m/s^2[/tex]
t is the time taken for the paintball to hit the ground
So
[tex]45 = 0* t + \frac{1}{2} 9.8 * t^2[/tex]
=> [tex]t = 2.143 \ s[/tex]
Generally the distance of its landing position from the tower is
[tex]d = v * t[/tex]
=> [tex]d = 90 * 2.143[/tex]
=> [tex]d = 192.86 \ m[/tex]
Why are recessive traits not seen even though they are present in the alleles?
Answer:
Explanation:. The vending machine holds 10 bags of pretzels and 8 packs of cheese crackers. Both the pretzels and crackers dispenseat 2 bags per hour. How many hours will elapse when there is the same number of snacks remaining in the vending machine? How many of each item will there be at this point?Equation1______________________________Equation2_______________________________Hours: ___________________________ Items: ____________________________What does each equation have n common? ______________________How does this affect the solution?
what is the number of significant digits in the measurement 10.005m?
A horse accelerates from rest for 1 s and covers a distance D. If instead the accelerates from rest with the same accelerations for 2 s will the distance it covers be equal to 2D, 4D, or 9D
Answer:
4D
Explanation:
We will use 2nd equation of motion in this question:
s = Vi t + (0.5)gt²
where,
s = distance covered
t = time taken
g = acceleration due to gravity
For t = 1 s:
s = D
Therefore,
D = (0 m/s)(1 s) + (0.5)g(1 s)²
D = 0.5g -------------- equation (1)
For t = 2 s:
s = D
Therefore,
s = (0 m/s)(1 s) + (0.5)g(2 s)²
s = 0.5g(4)
using equation (1):
s = 4D
therefore, correct answer is:
4D
Can some one help me please and thanks
Answer:
The way in which objects exert forces on each other is described by Newton’s 3rd law of motion
Explanation:
Objects with mass exert forces on each other via the force of gravity. This force is proportional to the mass of the two interacting objects and is inversely proportional to the square of the distance between them. The factors G, M, and rare the same for all masses at the surface of the Earth.
While spending the weekend in your cabin, you burn wood in your pot-bellied stove to heat a kettle of water for tea.
Answer the following questions for 2 points each:
1. What type of energy does the wood have in this situation. Explain your answer.
2. What type of energy is this transformed into as the wood it burned in the stove. Explain your answer.
3. What type of heat transfer is being used to warm the kettle of water? Why does the water eventually boil?
Answer: 1 = Heat
2=gas
3=it gets hot enough to boil because the metal conducts the heat into the water to heat it up and eventually boil.
Explanation: its common sense
pls help me tbis is being timed
Answer:
it would have to be 1000 netons
A truck moving due south takes a turn and starts moving towards east while maintaining the same speed.
Its velocity remains constant.
It covers unequal distances in equal intervals of time.
Its velocity changes
None of the above
Answer:
Its velocity changes
Explanation:
When the truck changes direction, its velocity changes.
Velocity is a vector quantity that specifies the magnitude of motion and direction it is taking.
When direction changes, the velocity of a body will also change. This is unlike speed which is a scalar quantity.
Velocity is the displacement divided by time taken.
where is the centripetal force directed on a banked curve?
Answer:
The net force on a car traveling around a curve is the centripetal force, Fc = m v2 / r, directed toward the center of the curve.
Explanation:LET ME KNOW IF ITS WRONG. HAVE A NICE DAY!!!!!!!!!!
Answer: The net force on a car traveling around a curve is the centripetal force, Fc = m v2 / r, directed toward the center of the curve. The centripetal force is directed at right angles to the motion and also along the radius towards the centre of the circular path. In order for a car to move around a circular track, something must provide a centipetal force. One source of the centripetal force is friction between the tires and the road. This means that the tires do not need to supply any friction at all to keep the car from slipping sideways. ...
Hope this helps... stay safe and have a great day!!! :D