A child pushes his younger brother with 54 newtons of force, causing him to accelerate at 3.8 m/s/s. Assuming no friction, what is the mass of the younger brother?
Answer to one decimal.
Answer:
force normal = mass times acceleration
F=ma
54= m (3.8)
divide by 3.8 in both sides
54/3.8
mass of the little brother is 14.2 kg
Which of the following best describes refraction?
Answer:
The medium sound waves
Explanation:
change in the direction of a wave passing from one medium to another.
Identify the type of motion that occurs when a body moves around its own center of mass.
circular
revolution
rotation
resolution
Answer:
circular
Explanation:
!!!!!!!!!!!!!!!!!!PLEASE HELP QUICK 30 BRAINLY POINTS!!!!!!!!!!!!!!
A two-stage rocket accelerates from rest at +3.57 m/s/s for 6.82 seconds. It then
accelerates at +2.98 m/s/s for another 5.90 seconds. After the second stage, it enters
into a state of free fall. Determine:
a. the maximum speed
b. the maximum altitude
c. the height of the rocket after 20.0 seconds
d. the total time the rocket is in the air (assuming it is launched from the ground)
!!!!!!!!!!!!!!!!!!PLEASE HELP QUICK 30 BRAINLY POINTS!!!!!!!!!!!!!!
Answer:
i need points
Explanation:
i need points
Answer:
this is old so-
Explanation:
PLS I NEED HELP ASAAP
Answer:
Option A
Explanation:
The Equation represents the displacement of the object which is represented by x
[tex]x=t-t^2[/tex]
so, [tex]x_0[/tex] means when time is zero so we replace t with zero in the equation,
[tex]x_0=(0)-(0)^2\\x_0=0[/tex]
now for v which is velocity we need to differentiate the function as the formula for velocity is rate of change of displacement over time so we derivate the equation once and get,
[tex]v=1-2t\\[/tex]
now for [tex]v_0[/tex] we insert t = 0 and get
[tex]v_0=1-2(0)\\v_0=1[/tex]
now for a which is acceleration the formula of acceleration is rate of change of velocity over time, so we differentiate the the equation of v(velocity) once or the equation of x(displacement) twice so now we get,
[tex]a=-2[/tex]
so Option A is your answer.
Remember derivative of a constant is always zero because a constant value has no rate of change has its a constant hence the derivative is 0
1) TRUE/FALSE, an example of a quantitative observation is “That is a red doll.”
2) TRUE/FALSE, Potential energy is strongest at the top of a hill.
3) F= ?, m= 18 kg, a= 2 m/s2
help me pweeeees
Answer:
1) False
2) True
3) 36N
Explanation:
1) Quantitative observation is related to number of objects . But in that example , there isn't any number.
2) Potential energy depends on height. So potential energy increases when height increases.
3) F = m×a
In the question , m = 18 kg ; a = 2m/s^2
So, F = 18×2 = 36N
If a wave has a velocity of 100m/s and a wavelength of 10m, what is the frequency?
What type of force is magnetic force? *
Strong Nuclear force
Non-contact force
Contact force. Weak Nuclear force
Answer:
non contant force
Explanation:
bcoz they push or pull on object without touching them
Answer:
energy
Explanation:
hand pushes on table with force of 35 N forward. whats the reaction force
Answer:
i think it is newtons third law of motion but i'm not sure sorry.i just really need point i don't know the answer.
Explanation:
Which of the following is an example of light energy being changed to chemical energy?
A flashlight with rechargeable batteries
A solar panel that charges a battery
Food that is eaten to provide mechanical energy
A switch that flips up to turn on a light
Answer:
solar panels that charges battery
i’ll literally venmo you if you answer this with FULL EXPLANATION so i can understand please !
Answer:
The speed with which the man flies after hitting the rock is 5.5 m/s
Explanation:
The given parameters are;
The mass of the man, m₁ = 100 kg
The mass of the scooter, m₂ = 10 kg
The initial speed of the man and the scooter, v₁ = 5 m/s
The speed with which the man flies after hitting the rock = v₂
The final speed of the scooter, v₃ = 0 m/s
The momentum = Mass × Velocity and by the principle of conservation of momentum, we have;
The total initial momentum = The total final momentum
The total initial momentum = (m₁ + m₂) × v₁ = (100 + 10) × 5 = 550
The total initial momentum = 550 kg·m/s
The total final momentum = m₁ × v₂ + m₂ × v₃, which gives;
The total final momentum = 100 × v₂ + 10 × 0
By conservation of momentum, the total initial momentum = The total final momentum, we get;
550 = 100 × v₂ + 10 × 0
∴ 550 = 100 × v₂
v₂ = 550 kg·m/s/(100 kg) = 5.5 m/s
The speed with which the man flies after hitting the rock = v₂ = 5.5 m/s
The axis of a circular cylinder coincides with the z-axis and it rotates with an angular velocity of (3i−5j +9k) rad/s. Determine i. The tangential velocity at a point P on the cylinder, whose co-ordinates are ( j +5k) metres,
Answer:
The tangential velocity at point P is [tex]\vec v_{P} = -34\,\hat{i} -15\,\hat{j}+3\,\hat{k}\,\,\left[\frac{m}{s} \right][/tex].
Explanation:
Vectorially speaking, we define tangential velocity at point P ([tex]\vec v_{P}[/tex]), measured in meters per second, by the following vectorial expression:
[tex]\vec v_{P} = \vec \omega \times \vec r_{P}[/tex] (1)
Where:
[tex]\vec \omega[/tex] - Angular velocity of the cylinder, measured in radians per second.
[tex]\vec r_{P}[/tex] - Radius of rotation, measured in meters.
If we know that [tex]\vec \omega = 3\,\hat{i}-5\,\hat{j}+9\,\hat{k}\,\left[\frac{rad}{s} \right][/tex] and [tex]\vec r_{P} = \hat{j}+5\,\hat{k}\,[m][/tex], then the tangential velocity at point P is:
[tex]\vec v_{P} = \left|\begin{array}{ccc}\hat{i}&\hat{j}&\hat{k}\\3\,\frac{rad}{s} &-5\,\frac{rad}{s} &9\,\frac{rad}{s} \\0\,m&1\,m&5\,m\end{array}\right|[/tex]
[tex]\vec v_{P} = \left[\left(-5\,\frac{rad}{s} \right)\cdot (5\,m)-(1\,m)\cdot \left(9\,\frac{rad}{s} \right)\right]\,\hat{i}-(5\,m)\cdot \left(3\,\frac{rad}{s}\right)\,j +\left(3\,\frac{rad}{s} \right)\cdot (1\,m)\,\hat{k}[/tex]
[tex]\vec v_{P} = -34\,\hat{i} -15\,\hat{j}+3\,\hat{k}\,\,\left[\frac{m}{s} \right][/tex]
The tangential velocity at point P is [tex]\vec v_{P} = -34\,\hat{i} -15\,\hat{j}+3\,\hat{k}\,\,\left[\frac{m}{s} \right][/tex].
A fireboat is to fight fires at coastal areas by drawing seawater with a density of 1030 kg/m3 through a 10-cm-diameter pipe at a rate of 0.04 m3/s and discharging it through a hose nozzle with an exit diameter of 5 cm. The total irreversible head loss of the system is 3 m, and the position of the nozzle is 3 m above sea level. For a pump efficiency of 70 percent, determine the required shaft power input to the pump and the water discharge velocity.
Answer:
50.93 m/s
199.5 kW
Explanation:
From the question, the nozzle exit diameter = 5 cm, Radius= diameter/2= 5cm/2= 2.5cm. we can convert it to metre for unit consistency= (2.5×0.01)=
0.025m
We can calculate the The cross sectional area of the nozzle as
A= πr^2
A= π ×0.025^2
= 1.9635 ×10^- ³ m²
From the question, the water is moving through the pipe at a rate of 0.1 m /s , then for the water to move through it at a seconds, it must move at
(0.1 / 1.9635 ×10^- ³ m²)
= 50.93 m/s
During the Operation of the pump, the Dynamic energy of the water= potential energy provided there is no loss during the Operation
mgh = 1/2mv²
We can make "h" subject of the formula, which is the height of required head of water
h = (1/2mv²)/mg
h= v² / 2g
h = 50.93² / (2 ×9.81)
h = 132.21m
From the question;
The total irreversible head loss of the system = 3 m,
the given position of nozzle = 3 m
the total head the pump needed=(The total irreversible head loss of the system + the position of the nozzle + required head of water )
=(3 + 3 + 132.21m)
=138.21m
mass of water pumped in a seconds can be calculated since we know that mass is a product of volume and density
Volume= 0.1m³
Density of sea water=1030 kg/m
(0.1 m^3× 1030)
= 103kg
We can calculate the Potential enegry, which is = mgh
= (103 ×9.81 × 138.21)
= 139651.5 Watts
= 139.65kW
To determine required shaft power input to the pump and the water discharge velocity
Energy= efficiency × power
But we are given efficiency of 70 percent, then
139651.5 Watts = 0.7P
=199502.18 Watts
P=199.5 kW
Therefore, the required shaft power input to the pump and the water discharge velocity is 199.5 kW
In interactions of action-reaction pairs involving Earth and everyday objects, the effect on Earth's motion is often negligible because
Answer:
...The earth has a great mass. Since mass and inertia are directly proportional to each other, the larger the mass of the object, the more inertia that it has. Inertia is the objects resistance to a change in motion.
Explanation:
A rock is dropped into a canyon that is 0.3 km deep. Determine the time it takes the rock to hit the bottom of the canyon?
Answer:
rock of mass m is dropped to the ground from a height h. A second rock, with mass 2m, is dropped from the same height. When the second rock strikes the ground, what is its kinetic energy? (a) Twice that of the first rock, (b) four times that of the first rock, (c) same as that of the first rock, (d) half as much as that of the first rock, (e) impossible to determine.
If a rock is dropped into a canyon that is 0.3 km deep, then the time taken by the rock to hit the bottom of the canyon would be 7.82 seconds.
What are the three equations of motion?There are three equations of motion given by Newton
v = u + at
S = ut + 1/2 × a × t²
v² - u² = 2 × a × s
Keep in mind that these calculations only apply to uniform acceleration.
As given in the problem, if a rock is dropped into a canyon that is 0.3 km deep.
By using the second equation of motion given by Newton,
S = ut + 1/2at²
300 = 0 + 0.5 × 9.8 × t²
t² = 300 / 4.9
t = 7.82 seconds
Thus, the time taken by the rock to hit the bottom of the canyon would be 7.82 seconds.
To learn more about equations of motion here, refer to the link given below ;
brainly.com/question/5955789
#SPJ2
41. What effects the efficiency of a pulley?
a. the type of rope or cable
b. the way the wheel turns
c. the length of the rope
d. how big the wheel is
e. only a and be
f. all of the above
Answer:
e. only a and b
What do we know about the relative strength of the electric field around each object?
Answer:
A charged object in an electric field experiences a force due to the field. The electric field strength, E, at a point in the field is defined as the force per unit charge on a positive test charge placed at that point.
Explanation:
This equation shows the reaction that occurs when charcoal burns. What type
of reaction is it?
Explanation:
Exothermic
Because here Energy is released.
Answer:
c
Explanation:
A soccer player kicks a ball 6.5 meters. How much time is needed for the ball to travel this distance if its velocity is 22 meters per second?
. . .
. . .
. . .
!
.
Your answer is 0.30 seconds
1. Four identical elephants are at different heights. If your physics teacher
asked you which of the following elephants has the greatest amount of
potential energy, what will be your answer? And why?
Helpppp:(((((
A 10 N force and an 18 N force act in the same direction on an object. What is the net force on the object?
Answer:
28 N
Explanation:
From the question given above, we were told that 10 N force and 18 N force act in the same direction on the object.
The net force acting on the object can be obtained by simply adding both forces together since they both act on the object in the same direction. This is illustrated below:
Force 1 (F₁) = 10 N
Force 2 (F₂) = 18 N
Net force (Fₙ) =?
Fₙ = F₁ + F₂ (since they both act in the same direction)
Fₙ = 10 + 18
Fₙ = 28 N
Therefore, the net force acting on the object is 28 N.
What two things does force depend on
Answer:
When dealing with the force of gravity between two objects, there are only two things that are important – mass, and distance or (acceleration)
Explanation:
Plz di all plz i will give brainest and thanks to best answer do it right
Answer:
B
hdhdududydysgd
hdhdgdtdtdt
gsgdgdggd
Explanation:
I TIHNK IS THE ANSWER
Answer:
C
Explanation:
Wave length is - - - - >
Bsjejwakknsbsbehebebbdbdbs
why are incandescent lights fo inefficient?
Answer:
Explanation:
Incandescent bulbs are extremely inefficient because 90% of the energy is wasted as heat, with only 10% being converted to visible light. This gives incandescent bulbs a luminous efficiency rating of around 2%. Ultimately, incandescent bulbs perform better as heaters than as light sources.
Why can't 41 be represented in a binary table?
Answer:
I think it is but I don't know for sure
Explanation:
41 101001
41 is 101001 on the binary table i think
Who might be suffering from dissociative fugue?
Answer:
More common in adults.
Explanation:
a 50.0kg skydiver experience a 740newton air resistance force determine her acceleration please help asap
Answer:
a = - 5 [m/s²].
Explanation:
To solve this problem we must use Newton's second law, which tells us that the sum of forces on a body is equal to the product of mass by acceleration.
∑F = m*a
where:
F = resultant force [N] (units of Newtons)
m = mass = 50 [kg]
a = acceleration = 9.81 [m/s²]
For this particular problem, the only forces acting are the force of gravity acting down with negative sign, while the force of air opposes the fall, in this way it is positive.
[tex]f_{air}-F_{grav}=-m*a[/tex]
As the movement is pointing down the acceleration will be taken as negative.
[tex]740-(50*9.81)=-50*a\\740-490.5 = -50*a\\249.5 = -50*a\\a = - 5 [m/s^{2} ][/tex]
We should note that in this case, the acceleration has a negative sign, this means that the force of the air makes the skydiver move upwards
HELP ASAP TIMER
Three trains are all are moving along a track with the same speed and slam on their brakes. If all three trains have identical coefficients of kinetic friction with the rail surface, which train travels the longest distance to come to a stop?
a
This cannot be determined, without knowing the normal force on the train by the rail.
b
The most massive train.
c
They all travel the same distance in stopping.
d
The least massive train.
Answer:
the more massive train i think
Explanation:
more mass means kinda more energy so it will take it longer to slow since it is larger
D. Ampere
A screw of length 5 cm enters totally into a wooden block after 25 turns. What is the pitch of the
screw?
A. 0.1 cm
B. 0.2 cm
C. 0.4 cm
D. 0.5 cm
Answer:
0.5
Explanation:
u must simplyfiy
Particles in which state of matter are the most likely to interact with each other to cause a chemical reaction?