Complete Question
In a ballistics test, a 21 g bullet traveling horizontally at 1200 m/s goes through a 35-cm-thick 300 kg stationary target and emerges with a speed of 950 m/s . The target is free to slide on a smooth horizontal surface.
a
How long is the bullet in the target? ____ s
b
What average force does the bullet exert on the target? _____ N
c
What is the target's speed just after the bullet emerges? _____ m/s
Answer:
a
[tex]t =3.256*10^{-4} \ s[/tex]
b
[tex]F = 16124 \ N[/tex]
c
[tex]v_1 = 0.0175 \ m/s[/tex]
Explanation:
From the question we are told that
The mass of the bullet is [tex]m = 21 \ g = 0.021 \ kg[/tex]
The horizontal speed is [tex]u =1200 \ m/s[/tex]
The thickness is [tex]s = 35 \ cm = 0.35 \ m[/tex]
The mass of the block is [tex]m_1 = 300 \ kg[/tex]
The emerging speed is [tex]v = 950 \ m/s[/tex]
Generally from kinematic equation
[tex]v^2 = u^2 + 2as[/tex]
So
[tex]a = \frac{v^2 - u^2}{2s}[/tex]
=> [tex]a = \frac{ 950^2 - 1200^2}{2 * 0.35}[/tex]
=> [tex]a = -767857.14 \ m/s^2[/tex]
Gnerally the time taken is mathematically represented as
[tex]t = \frac{ v- u}{a}[/tex]
=> [tex]t = \frac{ 950 - 1200}{-767857.14}[/tex]
=> [tex]t =3.256*10^{-4} \ s[/tex]
Generally from law of momentum conservation we
[tex]m *u + m_1 * u_1 = m * v + m_1 * v_1[/tex]
[tex]u_1[/tex] is the velocity of the block at rest which is [tex]u_1 = 0 \ m/s[/tex]
=> [tex]0.021 *1200 + 300 * 0 = 0.021 * 950 + 300 * v_1[/tex]
=> [tex]v_1 = 0.0175 \ m/s[/tex]
Generally the force is mathematically represented as
[tex]F = \frac{m_1 * v_1 }{t}[/tex]
=> [tex]F = \frac{300 * 0.0175 }{3.256 *10^{-4}}[/tex]
=> [tex]F = 16124 \ N[/tex]
A hockey puck with a mass of 0.17 kg is traveling to the right along the ice at 15 m/s. It strikes a second hockey puck with a mass 0.11 kg. The first hockey puck comes to rest after the collision. What is the initial momentum of the system? Round to the nearest tenth.
Answer: 2.6
Explanation: Just trust me...
A ball is thrown straight up in the air with a velocity of 12 m/s. Find the maximum height the ball reaches.
Show your work
Answer:
7.35 m
Explanation:
We can solve with kinematics or with energy.
Using kinematics, given:
v₀ = 12 m/s
v = 0 m/s
a = -9.8 m/s²
Find: Δy
v² = v₀² + 2aΔy
(0 m/s)² = (12 m/s)² + 2 (-9.8 m/s²) Δy
Δy = 7.35 m
Using energy instead:
PE = KE
mgh = ½ mv²
gh = ½ v²
h = v² / (2g)
h = (12 m/s)² / (2 × 9.8 m/s²)
h = 7.35 m
Darth Vader uses his powers to accelerate a 650.00 kg spaceship from rest to 100.00 m/s in 7.0 s. What is the net force on the spaceship?
Answer:
This Means Nothing to ME
Explanation:
I HAVE A tradition of doing a little analysis on one of my favorite movie franchises to celebrate Star Wars Day (May the Fourth Be With You). Given that Rogue One: A Star Wars Story recently appeared on DVD and various streaming services, I think its OK to look at that film without worrying about spoilers. In this case, I will calculate Darth Vader's power output as he uses the Force.
To calculate the power needed to lift this poor fellow, I can estimate how high Vader lifts him and at what speed. If I guess that the rebel is 1.75 meters tall (the average height of a man here on Earth, so I'll assume the same holds true on whatever planet the rebel calls home) then I can get an approximate scale for the scene. With that, I can use video analysis to plot the vertical position of the rebel as a function of time
Give three reasons why it’s important to give children opportunities to pretend play or have make-believe situations
Answer:
The first reason for children to have pretend play is that it allows the child to learn how to interact socially. The child is able to take turns, share responsibility, develop how people feel and react the situation. Another reason is that it helps the child develop their critical thinking skills. They may have to creatively solve a problem, or think what they may need in real life for the pretend play. It increases the child's ability to think through those types of situations. The final reason it is important for a child to have pretend play is that it helps develop their language skills. If the child is imitating a dad, mom, teacher, etc. they will attempt to use the same language that person uses. This helps the child connect new language abilities and skills.
Explanation:
Answer:
The top 3 reasons for encouraging children to pretend play and make-believe include:
1. To encourage imagination and creativity.
2. To support social and emotional development.
3. To improve language and communication skills.
some benefits of driver less cars
Benefits of Driverless Cars:
Reduced pollution and emissionsIncrease in road safety resulting in fewer accidentsImproved fuel economyLower fuel consumptionReduced trafficReduced travel time and transportation costsMore accessibility for those that can't driveLane capacity is increasedA geologist has collected this data about the rock ages in a certain area.
If generating a key for this data, what is the correct sequence from bottom to top?
a. C A B D E
Selected:b. E D B A CThis answer is incorrect.
c. E D C B A
d. A B C D E
Answer:
C A B D E
Explanation:
The newest rocks are always on top, and the oldest rocks are on the bottom.
C. 305 million
A. 200 million
B. 68 million
D. 3 million
E. 800 thousand
Please help me to answer this.... I will mark as BRAINLIEST whoever answers the best!!!
Answer:
the first lens is a converging lens also called biconvex lens
and second is a diverging lens called biconcave lens
Explanation:
What happens to energy when elastic objects interact with other objects?
What is the weight of a 44-kg child?
Answer:
89-95 lbs :p
Explanation:
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6. _____ When the nuclei of lighter atoms are combined to make heavier atoms: a. Nuclear Fusion b. Nuclear Fission c. Chemical Energy d. Atomic Bombs
Answer: The correct option is A.
Nuclear fusion.
Explanation:
It is nuclear fussion because nuclear fussion is the process whereby two or more lighter atomic nuclei come together that the forces that pull them together surpasses the forces that might pull them away making them to combine together to form heavier atomic nuclei. Energy is released in nuclear fusion.
A sprinter reaches a velocity of 2 m/s in just 1 second. At a constant rate of acceleration, how long does it take for her to double this velocity? What is her acceleration during this time period? Show you work and explain your answer.
Answer:
See the answer below
Explanation:
Acceleration is the ratio of velocity and time. Hence;
Acceleration of the sprinter = 2/1 = 2 m/s2.
When the acceleration is constant and the velocity is double:
acceleration = velocity/time
2 = 4/time,
time = 4/2 = 2 s
Hence, the time it will take for the velocity to double with constant acceleration is 2 s. The sprinter's acceleration during this period would be 2 m/s2.
Acceleration is the change in velocity with time. Hence, the time taken to double velocity is 2 seconds and the constant value of acceleration is 2m/s²
Acceleration is the change in velocity with time ;
Acceleration = (△velocity) ÷ time Velocity = 2m/s ; time = 1 secondAcceleration = (2 ÷ 1) = 2m/s²
Double the value of velocity = 2(2m/s) = 4m/s
At constant acceleration ; Acceleration = 2m/s²
Inputting the Values into the equation :
2 = 4 / time
(2 × time) = 4
Time = 4/2
Time = 2 seconds
Therefore, the time taken to double the velocity is 2 seconds
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How are forensic anthropologists and archaeologists different? A. Forensic anthropologists study bodies, and archaeologists search for artifacts. B. Forensic anthropologists study bodies, and archaeologists only study buildings. C. Forensic anthropologists study artifacts, and archaeologists study bodies. D. Forensic anthropologists study buildings, and archaeologists study bodies.
Answer:
A
Explanation:
Forensic anthropology is a branch of anthropology that analyzes the remains of a body in order to solve criminal cases. A forensic anthropologist, therefore, is a scientist that studies and analyzes remains of bodies in order to unravel criminal cases.
Archaeology, on the other hand, has to do with the analyses of artifacts in relation to human culture. An archaeologist is a person that studies artifacts mainly.
Hence, while a forensic anthropologist specializes in the study of bodies, archaeologist searches and studies artifacts.
The correct option is A.
a car is driving down a road in the early morning when a deer walks into the road. if the deer was 25 meters away when the driver noticed it and the car was traveling 20m/s, did the car strike the deer?
Answer:
For the car not to strike the deer, the minimum deceleration should be 8 m/s² with a combined instantaneous drivers reaction
Therefore, weather the deer is struck by the car depends on the drivers reaction time and deceleration of the car
Explanation:
The given parameters are;
The distance away from the deer the car was when the driver notices the deer = 25 m
The speed of the car = 20 m/s
Therefore, for the car not to strike the deer, the minimum deceleration of the car should be from 20²/(2 × 25) = 8 m/s² for an instantaneous driver reaction time
For a driver reaction time of 0.5 seconds, we have
Distance moved by car = 0.5 × 20 = 10 meters
Distance of the car from the deer at the start of deceleration = 25 - 10 = 15 meters
Minimum deceleration of the car required = 20²/(2 × 15) = 13.[tex]\bar 3[/tex] m/s²
For the car not to hit the deer, the minimum deceleration should be 8 m/s² with instantaneous driver's reaction.
Car hit the deer will depend on the driver's reaction time and deceleration of the car,
Given here,
Distance, when driver notice the deer = 25 m
Speed of the car = 20 m/s
So, the minimum deceleration
[tex]\bold {= \dfrac {20^2 }{2\times 25} = 8\ m/s^2 }[/tex]
Therefore, for the car not to strike the deer, the minimum deceleration of the car should be 8 m/s² with an instantaneous driver reaction time.
To know more about decceleration,
https://brainly.com/question/4403243
HELP PLEASE ASAP, 10 POINTS!
Answer:
2 is answer B.
3 is answer D.
3 is answer D because of the fears as to what happened with Chernobyl.
I hope this helps.
Which of the following accurately describes how a magnetic motor works
a
A set of electric coils are placed in a magnetic field. When a current passes through the wire, it creates a reaction that causes the atoms to being to shift into place
b
A set of electric coils are placed in a magnetic field. When a current passes through them, they create a magnetic field which interacts with the first magnetic field, causing the set of coils to rotate
c
A set of magnets are placed in an electric field. As the current increases or decreases, the strength of the electric field changes, causing the magnet to be more or less moved by the field
d
A set of magnets are placed in an electric field. A current is run through the magnets, thus increasing their magnetic fields. Once the magnetic field is increased, the magnets can be manipulated by the electric field by being guided around
Answer:
The correct option is;
c. A set of magnets are placed in an electric field. As the current increases or decreases, the strength of the electric field changes, causing the magnet to be more or less moved by the field
Explanation:
A permanent magnet motor is an electric motor that utilizes permanent magnets combined with a coil of electric wire winding rather than there being only the the electric wire windings in the motor
The principle of operation of a permanent magnet motor involves the rotation of a magnetic rotor by the electromagnetic force generated from the outer stator coil when power is supplied to the stator windings from an external source.
A skyjumper freely falls for 7 s. What is her final speed then?
Answer:
if we ignore air resistance .. which might slow her down a lot towards the end of the 7 seconds.. but we will just ignore that for this question
Explanation:
then V=Vo+a*t
Vo=0
V=a*t
V=9.8(7)
V=68.6 m/s just a little over 150 MPH.. but.. I think terminal velocity is close to 120... soo hmm maybe about that fast... but that with air resistance.. so this problem depends a lot on if you're going to ignore that
A boy climbs to the roof of his house and throws a rock at a horizontal velocity of 11.5 m/s. The rock lands on the ground, 15.3 m from the base of the house. How high is the roof of the house?
Answer:
The roof of the house is 8.67 m high
Explanation:
Horizontal Motion
When an object is thrown horizontally with a speed v from a height h, the range or maximum horizontal distance traveled by the object can be calculated as follows:
[tex]\displaystyle d=v\cdot\sqrt{\frac {2h}{g}}[/tex]
The boy is on the roof of his house and throws a rock horizontally at v=11.5 m/s. It lands on the ground d=15.3 m from the base of the house. We can use the above equation to find the height of the roof by solving it by h:
[tex]\displaystyle h=\frac{gd^2}{2v^2}[/tex]
Substituting values:
[tex]\displaystyle h=\frac{9.8\cdot 15.3^2}{2\cdot 11.5^2}[/tex]
h=8.67 m
The roof of the house is 8.67 m high
4. Maria wondered if different colors (red, orange, yellow, green, blue, and purple) of plastic wrap affected the time for bread to mold. She also wrapped a slices of bread in clear plastic wrap to see how they may normally mold. Before wrapping the same type of bread (Wonder Whole Wheat), she placed 5 ml of water in the center of each slice. The slices were of the same size and wrapped in the same manner and kept in a dark space at 75 degrees Fahrenheit. She measured the area of mold growth for one week after the mold first appeared. She observed 25 slices of bread for each color of wrap and the clear wrap as well. what is the constant variable the independant variable and the depentant variable
Answer:
Constant variable: SAME TYPE OF BREAD (Wonder whole wheat), SAME AMOUNT OF WATER (5ml), SAME SIZE OF BREAD SLICE, SAME TEMPERATURE (75°F)
Independant variable: COLORS OF PLASTIC WRAP
Depentant variable: TIME FOR BREAD TO MOLD
Explanation:
In any experiment, the independent variable is the variable that is deliberately changed or manipulated by the experimenter. In this case, the independent variable is the DIFFERENT COLORS OF PLASTIC WRAP USED (red, orange, yellow, green, blue, and purple).
Dependent variable is the variable that the experimenter measures in an experiment. It is the variable that responds to changes made to the independent variable. In this experiment, the dependent variable is the TIME IT TAKES FOR BREAD TO MOLD.
Constant variable, also known as Controlled variable, is the variable that the experimenter keeps constant or unchanged for all groups throughout the experiment. In this experiment, the constants are: SAME TYPE OF BREAD (Wonder whole wheat), SAME AMOUNT OF WATER (5ml), SAME SIZE OF BREAD SLICE, SAME TEMPERATURE (75°F)
is this right, please answer
The eyes, spinal cord, and brain are all main or key parts of the nervous system.
What are the products from Aluminum + Copper Chloride? Al + CuCl2
Answer:
hope this will help u
Explanation:
Al + CuCl2 => AlCl2 + Cu
A gas is currently at a temperature of 84º C at a volume of 10 liters. If the pressure is kept the same and the temperature is lowered to 72º C, what will the new volume be?
Answer:
9.66 L
Explanation:
The following data were obtained from the question:
Initial temperature (T1) = 84 ºC
Initial volume (V1) = 10 L
Final temperature (T2) = 72 ºC
Final volume (V2) =..?
Next, we shall convert celsius temperature to Kelvin temperature. This can be obtained as follow:
T(K) = T(°C) + 273
Initial temperature (T1) = 84 ºC
Initial temperature (T1) = 84 ºC + 273 = 357 K
Final temperature (T2) = 72 ºC
Final temperature (T2) = 72 ºC + 273 = 345 K
Since the pressure is constant, it means the gas is obeying Charles' law. Thus, we shall determine the new volume of the gas as follow:
Initial temperature (T1) = 357 K
Initial volume (V1) = 10 L
Final temperature (T2) = 345 K
Final volume (V2) =..?
V1/T1 = V2/T2
10/357 = V2/345
Cross multiply
357 × V2 = 10 × 345
Divide both side by 357
V2 = (10 × 345) / 357
V2 = 9.66 L
Thus, the new volume of the gas is 9.66 L.
A teacher placed 80 g of ice in a sealed plastic container at room
temperature.
How many grams of liquid water will be in the plastic container when the ice
has melted?
A. Slightly less than 80 g
B. Exactly 80 g
C. Slightly more than 80 g
D. The exact amount is unknown.
Answer: b
Explanation: Cause the other guy said it was
Answer:
The answer is B. Exactly 80 g
Explanation:
I just did the test and got it right!
Hope this helps.
A stone is thrown horizontally from the top of a 25.00-m cliff. The stone lands at a distance of
40.00 m from the edge of the cliff. What is the initial horizontal velocity of the stone?
The projectiles launch allows to find the answer for the initial velocity of the stone is:
v = 17.71 m / s
Projectile launching is an application of kinematics for motion in two dimensions, where there is no acceleration on the x axis and the acceleration on the y axis is the gravity acceleration.
In the attached diagram we can see a corner of the movement. Where the x axis is horizontal and the y axis is vertical, where the zero of the system is at the base of the cliff
In this case the stone is thrown horizontally, therefore its initial vertical speed is zero, let's find the time it takes to reach the base of the cliff
y = y₀ + [tex]v_{oy}[/tex] t - ½ g t²
where y and y₀ are the current and initial position, [tex]v_{oy}[/tex] is the initial vertical velocity, g the acceleration of gravity and t the time
When reaching the bottom its height is zero (y = 0) and the highest part its initial height is y₀ = 25.00 m
0 =y₀ + 0 - ½ g t²
t = [tex]\sqrt{\frac{2y_o}{g} }[/tex]
Let'se calculate
[tex]t = \sqrt{ \frac{2 \ 2.25 }{9.8 } }[/tex]
t = 2,259 s
They indicate that the stone fell at a horizontal distance of 40 m,
x = [tex]v_{ox}[/tex] t
v_{ox} = [tex]\frac{x}{t}[/tex]
v_{ox} = [tex]\frac{40}{2.259}[/tex]
v_{ox} = 17.71 m / s
In conclusion, using theprojectiles launch we can find the answer for the initial velocity of the stone is:
v = 17.71 m / s
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An object, initially traveling at a velocity of 52 m/s, experiences an acceleration of -9.8 m/s². How much time will it take it to come to rest? *
Answer:
5.3 s
Explanation:
Given:
v₀ = 52 m/s
v = 0 m/s
a = -9.8 m/s²
Find: t
v = at + v₀
0 m/s = (-9.8 m/s²) t + 52 m/s
t = 5.3 s
Help! Need answers for #1-5.
2 points
Make the following conversion: 0.95km to cm Hint: don't forget king
henry.......
*
95,000 cm
0.000095 cm
9,500 cm
95 cm
Answer:
95000cm
Explanation:
Given parameter:
0.95km
Problem;
Convert km to cm;
Solution:
100cm = 1m
1000m = 1km
So,
100,000cm = 1km
1km = 100,000cm
0.95km = 0.95 x 100000 = 95000cm
i will give u brainliest!
The answer is C. Hope this helps!
A car has an acceleration of -10.7 mph? What does this tell you about the motion of the care
A. It is speeding up
C. It is traveling at a constant speed
B. It is slowing down
D. It is traveling at a constant acceleration
Answer:
traveling at a constant acceleration
A person walks 200meters at 27 degrees north of East
Answer:
sdf
Explanation:
2. Marta was biking along the bike path at an average velocity of +4.2 m/s. If she biked for 800 seconds,
how far did she travel? (4 pts)
Answer:
3360m
Explanation:
Given parameters:
Average velocity of Marta = 4.2m/s
Time taken for biking = 800s
Unknown:
Distance traveled =?
Solution:
Velocity is the rate of change of displacement with time.
Displacement = velocity x time
Input the parameters and solve;
Displacement = 4.2 x 800 = 3360m