The initial speed of the bullet = v₁= 511.07 m/s
Further explanationGiven
17.4 g bullet
5506 g wooden
The velocity of the block+bullet :1.61 m/s
Required
The initial speed
Solution
Momentum
m₁v₁+m₂v₂=m₁v₁'+m₂v₂'
v₂=0 ⇒block at rest
v₁'=v₂'=1.61 m/s
the equation becomes :
m₁v₁=(m₁+m₂)v'
17.4v₁=(17.4+5506)1.61
v₁= 511.07 m/s
A hovercraft is being driven across a lake on a very windy day. The wind exerts a force of 5000 N north on the hovercraft. The propellers driving the hovercraft also exert a force.
What is the net force (to 3.s.f ) on the hovercraft when the force applied to the hovercraft by the propellers is: 10 000 N west
Answer:
The net force on the hovercraft is 11200 N.
Explanation:
Given;
force exerted on the hovercraft by wind, F₁ = 5000 N north
force exerted on the hovercraft by the propeller, F₂ = 10,000 N west
The net force on the hovercraft is calculated as;
[tex]F_{net} = \sqrt{F_1^2 + F_2^2} \\\\F_{net} = \sqrt{5000^2 + 10,000^2} \\\\F_{net} = 11180.34 \ N\\\\F_{net} = 11200 \ N \ (3.s.f)[/tex]
Therefore, the net force on the hovercraft is 11200 N.
A 20.0 N force is necessary to stretch a spring 0.500 m. What is the spring constant of this spring?
The spring constant : k = 40 N/m
Further explanationGiven
Force = 20 N
The displacement of the spring=x=0.5 m
Required
The spring constant = k
Solution
Hooke's Law
F = k.x
k = F/x
Input the value :
k = 20/0.5
k = 40 N/m
During a phase change the temperature of a substance remains constant this is because during a phase heat changes the ____ energy of particles in a substance without changing their ____ energy
Answer:
Explanation:
individual and then net
hope that helps I could be wrong about this one though
Two cellists, one seated directly behind the other in an orchestra, play the same note for the conductor who is directly in front of them. Because of the separation between the cellists, destructive interference occurs at the conductor. This separation is the smallest that produces destructive interference. Would this separation increase, decrease, or remain the same if the cellists produced a note with a higher frequency
Answer:
Please see below as the answer is self-explanatory.
Explanation:
In order to have a destructive interference, the path difference between the sources of the sound, must be equal to an odd multiple of the semi-wavelength, as follows: ⇒ d = d₂ - d₁ = n*(λ/2) The minimum posible value for this distance, is when n=1, as it can be seen here: dmin = λ/2 In any traveling wave, there exists a fixed relationship between the wave speed, the frequency and the wavelength: v = λ*f Therefore, assuming that the speed of sound keeps constant, if the frequency is increased, in order to keep the right side of the expression above balanced, λ must be decreased.As the smallest separation that produces destructive interference is directly proportional to the wavelength, this means that this separation will decrease if the cellists produced a note with a higher frequency.A spring with an unknown spring constant is hung vertically, and a 200 g (0.200 kg) mass is attached to the bottom. If the spring stretches 0.250 m from its resting position to the position at which the hanging mass is in equilibrium, what is the spring constant of this spring?
Answer:
k = 7.84 N/m
Explanation:
We are given;
Mass hanging object; m = 0.2 kg
Extension; Δx = 0.25 m
Now, formula for the force is;
F = k•Δx
Where k is the spring constant
Since we have mass, then F = W = mg = 0.2 × 9.8 = 1.96 N
Thus;
1.96 = k × 0.25
k = 1.96/0.25
k = 7.84 N/m
Physical science-current can be increased by...
Option 3.) Increasing the voltage across the wire.
I know that the other answers are incorrect because, for one thing, the more resistance in a substance, the less flow of the current there is. Also, using a longer wire doesn't change anything, it just makes a electrical current go on longer. Lastly decreasing the voltage would make the current decrease in the atoms that flow through it to power an object.
-R3TR0 Z3R0
A student drove to the university from her home and noted that the odometer reading of her car increased by 17.9 km. The trip took 26.6 min.
a) What was her average speed, in kilometers per hour?
b) IS she returned home by the same path 7 h 30 min after she left, what was her average speed and velocity for the entire trip?
Answer:
See calculation below
Explanation:
Average speed = Distance/Time
a) Given
Distance = 17.9km
Time = 26.6minutes
Time = 26.6/60 hr
Time = 0.443hr
Average speed = 17.9/0.443
Average speed = 40.38km/hr
b) If she returned home by the same path 7 h 30 min after she left, the distance will be the same;
Distance = 17.9km
Time = 7.5hr
Average speed = 17.9/7.5
Average speed = 2.387km/hr
Velocity of the entire trip = 40.38km/hr + 2.387km/hr
Velocity of the entire trip = 42.77km/hr
Hence the velocity of the entire trip is 42.77km/hr
When an object falls, its:
A. PE increases and KE decreases.
B. PE does not change.
C. PE and KE both increase.
D. PE decreases and kE increases
Answer:
Option D. is correct.
Explanation:
The object's mechanical energy refers to the sum of the potential and kinetic energies of the object. When an object falls, its potential energy (PE) decreases, and its kinetic energy (KE) increases. The increase in kinetic energy is exactly equal to the decrease in potential energy.
Option D. is correct.
If vec A and vec B are vectors and vec B = -vec A , which of the following is true ?
a) The magnitude of is equal to the negative of the vec B magnitude of vec A
b) Ā and vec B are perpendicular .
c) The direction angle of is equal to the direction angle of vec B A plus 180 degrees
d ) vec A + vec B =2 vec A .
Answer:
If A + B = C for the vector equation then substituting for B gives
A + (-A) = C = 0
The only thing that can be said about "C" is that it has zero magnitude.
Two stationary positive point charges, charge 1 of magnitude 3.95 nC and charge 2 of magnitude 1.80 nC, are separated by a distance of 39.0 cm. An electron is released from rest at the point midway between the two charges, and it moves along the line connecting the two charges.What is the speed of the electron when it is 10.0 cm from charge 1?
Answer:
the speed of the electron from charge q1 is 7.17×10⁶ m/s
Explanation:
Given the data in the question;
the potential at the center of the two charges will be;
V = k( q1/(d/2) + q2/(d/2)
so we substitute
V = (9×10⁹)( (3.95×10⁻⁹/(0.39/2) + 1.80×10⁻⁹/(0.39/2)
V = 265.4 V
the potential at a distance of 10 cm from the charges will be
V = k( q1/(d1) + q2/(d2)
(d1 = 10cm = 0.1m and d2 = 39cm - 10cm = 29cm = 0.29m )
V' = (9×10⁹)( (3.95×10⁻⁹/0.1 + 1.80×10⁻⁹/0.29
V' = 411.4 V
Now, from the conservation of energy the speed of the electron from charge q1 will be;
E = ( V' - V) qe
1/2mv² = ( V' - V) qe
v² = [( V' - V) qe] / 1/2m
v =√ ([( V' - V) qe] / 1/2m)
v =√ ([2( V' - V) qe] / m)
we substitute
v =√ (2[( 411.4 - 265.4) 1.6×10⁻¹⁹] / 9.1×10³¹)
v = 7.17×10⁶ m/s
Therefore, the speed of the electron from charge q1 is 7.17×10⁶ m/s
calculate the peak voltage of a mains supply of 240Vrms.
a car traveling at 30m/s slows down to a stop 10s. what is the acceleration?
Answer:
20 m/s. have a great day
Answer:
since v decreased by 20m/s in 5 sec, a = -4 m/s^2
assuming the 3 seconds started at t=0,
s = 30t - 2t^2
s(3) = 30(3) - 2(9) = 72m
A bird lands on a bird feeder which is connected to a spring. The mass of the bird is exactly the same as the mass of the bird feeder. How does the added mass affect the period of oscillation of the bird feeder?
Answer:
The added mass will mean a longer period of oscillation.
Explanation:
The period of oscillation here is given by the formula;
T = 2π√(m/k)
Where m is mass and k is spring constant
From the equation of oscillation period above, it's obvious that when we increase the mass, the oscillation period will also increase.
Thus, the added mass will mean a longer period of oscillation.
A 80 N force is needed to slide a 50.0 kg box across a flat surface at a constant velocity. What is the coefficient of kinetic friction between the box and the floor
Answer:
0.16
Explanation:
Given data
Force F= 80N
Mass m= 50kg
Reaction R= Weight= mg= 50*9.81= 490.5N
We know that
F=UR
Substitute and solve of U
U=F/R
U= 80/490.5
U=0.16
Hence the coefficient of friction is 0.16
What type of reaction is occurring when you activate an instant cold pack?
A. Endothermic, because energy is absorbed
B. Exothermic, because energy is released
O C. Endothermic, because energy is released
D. Exothermic, because energy is absorbed
Answer:
Endothermic, because energy is absorbed (A)
Explanation:
The reaction that take place in the instant cold pack causes the surroundings around it, including the bag that contains it. When the bag loses heat to the cold pack, the cold pack absorbs the heat, thereby causing the environment (the bag) to be cold.
I =p/4pir^2 solving for r
Answer: [tex]r = \sqrt{\frac{p}{4pil}}[/tex]
Explanation:
[tex]l = \frac{p}{4pir^2} \\4pir^2l=p\\r^2 = \frac{p}{4pil} \\r = \sqrt{\frac{p}{4pil}}[/tex]
5. (Liquids Gases) have particles with enough energy to spread out
throughoutcontainer. *
A)Liquids
B)Gases
Answer:
b gases
Explanation:
this is because gases spread out through out the entire container because they have no definite shape and are always moving.
Basketball player Darrell Griffith is on record as
attaining a standing vertical jump of 1.2 m (4 ft).
(This means that he moved upward by 1.2 m after
his feet left the floor.) Griffith weighed 890 N (200
lb). g=9.8 m/s2
1- What is his speed as he leaves the floor?
2- if the time of the part of the jump before his feet left the floor was 0.300s, what was the magnitude of his average acceleration while he was pushing against the floor?
Explanation:
1.
We use the equation
h = [tex]\frac{gt^2}{2}[/tex], where
h is the height traveled,
g is the acceleration due to gravity and
t is the time taken to reach height h.
We can now calculate t to be
[tex]\sqrt{\frac{2*1.2 m}{9.81 m/s^2} }[/tex]
= 0.495 s
Let v be the initial velocity of the player.
The player deaccelarates from v m/s to 0 m/s in 0.495 s at the rate of 9.81 m/s^2.
v = 9.81 m/s^2 x 0.495 s = 4.85 m/s
2.
The player takes 0.3 s to increase his velocity from 0 m/s to 4.85 m/s. So his average accelaration is
4.85 m/s / 0.3 s = 16.2 m/s^2
1. A plane starts from rest and aceelerates in a
straight line along the ground before take-off. It
moves 600 m in 12 s. Calculate the distance
moved during the twelfth second.
s=600 m
t=12 s
s=0.5*a*t² (initial speed V0=0)
a=(2*s)/t²
a=(2*600)/12²
a≈8.33 m/s²
L= s(t2=12s)-s(t1=11s) -> (distance during the twelfth second)
L=0.5*a*(t2²-t1²)
L=0.5*((2*s)/t²)*(t2²-t1²)
L=0.5*((2*600)/12²)*(12²-11²)
L ≈ 95.83 m
___is found in fruits and honey. *
1.Maltose
2.Sucrose
3.Fructose
4.Galactose
Answer:
3. Fructose
Explanation:
Fructose is a sugar found naturally in fruits, fruit juices, some vegetables and honey.
it is number 3 (Fructose)
4. Taylor Swift pushes Kanye West,
headfirst fearless, off a high dive with and
initial speed of 6m/s. If the platform is 20m
high, what is Kanye's impact velocity with
the water? (velocity and angle)
chinese wares are wrapped by piece of paper why
Answer:
chinawares are wrapped by paper while packaging to reduce the chances of the wares breaking when falling
Calculate P3 (in W). W (b) Find the total power (in W) supplied by the source. W Compare the total power with the sum of the powers dissipated by the resistors. (Consider two values to be equal if they are within 3% of each other.) The total power is less than the sum of the powers dissipated by the resistors. The total power is equal to the sum of the powers dissipated by the resistors. The total power is greater than the sum of the powers dissipated by the resistors.
Answer:
the principle of conservation of energy cannot be violated.
the correct one is: The total power is equal to the sum of the powers dissipated by the resistors.
Explanation:
The power in an electric circuit is given by
P == I V
In a circuit with several components (resistors) the power dissipated is the current by the voltage in each resistance, by the principle of conservation of energy the current in each resistance is the same if the circuit is in series and the current is the same if The circuit is in parallel, but cannot be greater than the current supplied by the power source.
Therefore, the power dissipated by the entire circuit is the sum of the power dissipated by each part, since the principle of conservation of energy cannot be violated.
When reviewing the answers, the correct one is: The total power is equal to the sum of the powers dissipated by the resistors.
Are you better off in an accident where the hood is
deformed or where the car is not damaged at all but
bounces backward?
Answer:
you would be better off if the car bounced backwards
Explanation:
because if the hood was dismembered than you have a high chance of very bad injury but if it is just bounced back you would have less chance of getting hurt if properly sitting and seat belted.
What is the total amount of kinetic and potential energy in a system ?
Answer:
Its the sum of the potential energy and the kinetic energy
A light rope is attached to a block with mass 3.60 kg that rests on a frictionless, horizontal surface. The horizontal rope passes over a frictionless, massless pulley, and a block with mass m is suspended from the other end. When the blocks are released, the tension in the rope is 18.8 N .
(a) Draw two free-body diagrams: one for each block.
(b) What is the acceleration of either block?
(c) Find m.
(d) How does the tension compare to the weight of the hanging block?
Answer and Explanation:
(a) The fre-body diagrams for each block is shown below. In the block of mass 3.60 kg, there are 3 forces acting on it: horizontal force due to the rope ([tex]F_{t}[/tex]), vertical gravitational force ([tex]F_{g}[/tex]) and vertical normal force ([tex]F_{n}[/tex]), due to the surface. Since there is no vertical movement, [tex]F_{g}[/tex] and [tex]F_{n}[/tex] cancels it out. So, for this block, net force is horizontal due to the rope [tex]F_{t}[/tex].
The block of mass m is hanging from the pulley, so there is the force of the rope ([tex]F_{t}[/tex]) and the gravitational force ([tex]F_{g}[/tex]). Both are vertical, because there is no surface "holding" block m.
(b) Since both blocks are attached to each other, the acceleration will be the same. To calculate it, we use the Second Law of Motion:
[tex]F_{r}=m.a[/tex]
[tex]a=\frac{F_{r}}{m}[/tex]
[tex]a=\frac{18.8}{3.6}[/tex]
a = 5.22
The acceleration of either block is 5.22 m/s².
(c) Block m has 2 forces acting on it: tension and gravitational force. Gravitational force is the force of attraction the Earth does over an object. It is calculated as the product of mass and gravitational acceleration, which has magnitude g = 9.8 m/s².
Suppose positive referential is going up. To determine mass:
[tex]F_{r}=m.a[/tex]
[tex]F_{t}-F_{g}=m.a[/tex]
[tex]F_{t}-m.g=m.a[/tex]
[tex]18.8-9.8m=5.22m[/tex]
[tex]15.02m=18.8[/tex]
m = 1.25
Block m has 1.25 kg.
(d) Gravitational force is also called weight. So, as described above: [tex]F_{g}=m.g[/tex].
The weight for the hanging block is
[tex]F_{g}=1.25*9.8[/tex]
[tex]F_{g}=[/tex] 12.25 N
Comparing tension and weight:
[tex]\frac{12.25}{18.8}[/tex] ≈ 0.65
We can see that, weight of the hanging block is almost 0.65 times smaller than the tension on the rope.
Which of the following statements are true?
a. By convention, the direction of a current is taken to be the direction of flow for negative charges.
b. When an electric field is applied to a conductor, the free electrons move only in the direction opposite the applied electric field.
c. Current is the total amount of charge that passes through a conductor's full cross section at any point per unit of time.
d. In order to maintain a steady flow of current in a conductor, a steady force must be maintained on the mobile charges.
e. In a circuit, current is delivered by the positive terminal of a battery, and it is used up by the time it returns to the negative terminal of the battery.
Answer:
A, C, D and E are the true statement about current flowing.
The bat emits a sound wave with a frequency of 25.0 kHz and a wavelength of 0.0136
metres.
Calculate the speed of this sound wave.
Answer:
The calculation that you then need to do is 25000 x 0.0136 = 340. You must not forget the units of speed, which here are metres per second, or m/s. Your final answer is 340 m/s.
An ideal monatomic gas initially has a temperature of 300 K and a pressure of 5.79 atm. It is to expand from volume 420 cm3 to volume 1450 cm3. If the expansion is isothermal, what are (a) the final pressure and (b) the work done by the gas
Answer:
a) The final pressure is 1.68 atm.
b) The work done by the gas is 305.3 J.
Explanation:
a) The final pressure of an isothermal expansion is given by:
[tex] T = \frac{PV}{nR} [/tex]
[tex] T_{i} = T_{f} [/tex]
[tex] \frac{P_{i}V_{i}}{nR} = \frac{P_{f}V_{f}}{nR} [/tex]
Where:
[tex]P_{i}[/tex]: is the initial pressure = 5.79 atm
[tex]P_{f}[/tex]: is the final pressure =?
[tex]V_{i}[/tex]: is the initial volume = 420 cm³
[tex]V_{f}[/tex]: is the final volume = 1450 cm³
n: is the number of moles of the gas
R: is the gas constant
[tex] P_{f} = \frac{P_{i}V_{i}}{V_{f}} = \frac{5.79 atm*420 cm^{3}}{1450 cm^{3}} = 1.68 atm [/tex]
Hence, the final pressure is 1.68 atm.
b) The work done by the isothermal expansion is:
[tex] W = P_{i}V_{i}ln(\frac{V_{f}}{V_{i}}) = 5.79 atm*\frac{101325 Pa}{1 atm}*420 cm^{3}*\frac{1 m^{3}}{(100 cm)^{3}}ln(\frac{1450 cm^{3}}{420 cm^{3}}) = 305.3 J [/tex]
Therefore, the work done by the gas is 305.3 J.
I hope it helps you!
You drive on Interstate 10 from San Antonio to Houston, half the time at 75 km/h and the other half at 106 km/h. On the way back you travel half the distance at 75 km/h and the other half at 106 km/h. What is your average speed (a) from San Antonio to Houston, (b) from Houston back to San Antonio, and (c) for the entire trip
Answer:
Explanation:
a ) from San Antonio to Houston let distance be d km .
Average speed = total distance / total time
time = distance / speed
Total time = (d / 2 x 75 ) +( d / 2 x 106 )
= .0067 d + .0047 d
= .0114 d
Average speed = d / .0114 d = 87.72 km /h
b ) from Houston back to San Antonio
Total time = (d / 2 x 106 ) +( d / 2 x 75 )
= .0047 d + .0067 d
= .0114 d
Average speed = d / .0114 d = 87.72 km /h
c )
For entire trip :
total distance = 2d
total time = 2 x .0114 d
Average speed = 2 d / 2 x .0114 d
= 87.72 km /h .