Answer:
The rock will hit the ground at 20.44 m from the point of the drop
Explanation:
Horizontal Motion
It occurs when an object is thrown horizontally from a height h at an initial speed v.
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]
When the small rock is dropped from a car at speed v=32 m/s, it starts a curved path that ends up when the rock hits the ground. The height is h=2 m, thus the range is:
[tex]\displaystyle d=32\cdot\sqrt{\frac {2\cdot 2}{9.8}}[/tex]
[tex]\displaystyle d=32\cdot\sqrt{0.4082}[/tex]
[tex]d=20.44\ m[/tex]
The rock will hit the ground at 20.44 m from the point of the drop
Grade 8 Science Admin. May 2018 Released
37 A physics teacher performed a demonstration for a science class by pulling a crate across the
floor and measuring the force with a spring scale. While she pulled, a student measured the
acceleration of the crate with a handheld electronic device. The results of three trials are
shown below
Motion
F = 900 N
Actual Acceleration
of Crate
Trial
1
140 kg
Acceleration
(m/s)
0.36
0.34
0.38
0.36
2
3
Average
The teacher asked the class to calculate the acceleration of the crate based on the crate's
mass and the force she applied. What conclusion can be made about the difference between
the calculated acceleration and the actual acceleration that occurred in the trials?
A Another force in the direction of the motion produced a lower acceleration than calculated.
B An opposing force caused by friction produced a lower acceleration than calculated.
C Another force in the direction of the motion produced a higher acceleration than
calculated.
D An opposing force caused by friction produced a higher acceleration than calculated,
Answer:
B. An opposing force caused by friction produced a lower acceleration than calculated
Explanation:
Answer:
An opposing force caused by friction produced a lower acceleration than calculated.
Explanation:
Newton's first law of motion states than an object's motion will not change
unless?
Answer:
it is hit by an external force
Explanation:
What is another name for an alpha particle? Include the atomic number and mass number
Answer:
Alpha particles are Helium nuclei consisting of 2 protons and two neutrons (mass number 4, atomic number 2, no electrons and so carry a 2+ charge).
Explanation:
what is an isoelectronic series
Answer:
A comparison of the dimensions of atom an ions that have the same number of electron but different nuclear charges is called isoelectronic series
Answer:
A comparison of the dimensions of atoms or ions that have the same number of electrons but different nuclear charges, called an isoelectronic series, shows a clear correlation between increasing nuclear charge and decreasing size
help pls!!! this is worth 30 points, can someone pls help even if u can only give a few answers it would be helpful.
Answer:
1. potential 2. kinetic 3. potential 4. kinetic 5. kinetic 6. kinetic 7. kinetic 8. kinetic. potential
What is the speed in kilometers per hour of a 27.78m/s baseball pitch?
Answer:
I actually don't know
Explanation:
ok chillll
Which reaction is an acid-base neutralization reaction?
A. Mg + 2HCl → MgCl2 + H2
B. HCl + NaOH → NaCl2 + H2O
C. SiCl4 → Si2 + 2Cl2
D. N2 + 3H2 → 2NH3
Answer:
option B is correct
Explanation:
neutralization is the reaction between acid and base to produce water and salt therefore option B is correct
An insulated rigid tank initially contains 1.4-kg saturated liquid water and water vapor at 200°C. At this state, 25 percent of the volume is occupied by liquid water and the rest by vapor. Now an electric resistor placed in the tank is turned on, and the tank is observed to contain saturated water vapor after 20 min. Determine:
(a) the volume of the tank
(b) the final temperature
(c) the electric power rating of the resistor
Solution:
Mass of liquid water and water vapor in the insulated tank initially = 1.4 kg
Temperature = 200 °C
And 25% of the volume by liquid water is steam.
State 1
[tex]$m=\frac{V}{v}$[/tex]
[tex]$m=m_f+m_g$[/tex]
[tex]$1.4=\frac{0.25V}{v_f}+\frac{0.75V}{v_g}$[/tex]
[tex]$1.4=\frac{0.25V}{1.1565 \times 10^{-3}}+\frac{0.75V}{0.1274}$[/tex] (taking the value of [tex]$v_g$[/tex] and [tex]$v_g$[/tex] at 200°C )
[tex]$V=6.304 \times 10^{-3}$[/tex]
Now quality of vapor
[tex]$x=\frac{m_g}{m}$[/tex]
[tex]$=3.377 \times 10^{-3}$[/tex]
Internal energy at state 1 can be found out by
[tex]$u_1=u_f+xu_{fg}$[/tex]
[tex]$=850.65+3.377\times10^{-3}\times 1744.65$[/tex]
= 856.54 kJ/kg
After heating with the resistor for 20 minutes, at state 2, the tank contains saturated water vapor [tex]$v_2=v_g \text { and }\ x=1$[/tex]
Tank is rigid, so volume of tank is constant.
[tex]$v_g=v_2=\frac{V}{m}$[/tex]
[tex]$v_g=\frac{6.304\times 10^{-3}}{1.4}$[/tex]
[tex]$v_g=4.502 \times 10^{-3} \ m^3 /kg$[/tex]
Now interpolate the value to get temperature at state 2 with specific volume value to get final temperature
[tex]$T_2=360+(374.14-360)\left(\frac{0.004502-0.006945}{0.003155-0.006945}\right)$[/tex]
= 369.11° C
Internal energy at state 2
[tex]$u_2=2154.9 \ kJ/kg$[/tex]
Now power rating of the resistor
[tex]$P=\frac{m(u_2-u_1)}{t}$[/tex]
[tex]$P=\frac{1.4(2154.9-856.54)}{20 \times 60}$[/tex]
= 1.51 kW
A system has both thermal energy and chemical potential energy. According
to the law of conservation of energy, which statement describes the total
energy of this system?
O A. It will decrease over time as chemical potential energy is
transformed into thermal energy.
B. It will decrease as thermal energy is transferred out of the system.
C. It will remain constant because the total amount of thermal energy
plus chemical potential energy stays the same.
OD. It will increase as thermal energy is created from chemical
potential energy
Answer:
C. It will remain constant because the total amount of thermal energy plus chemical potential energy stays the same.
Explanation:
According to the law of conservation of energy, the total energy of this system will remain constant because the total amount of thermal energy plus chemical potential energy stays the same.
The law of conservation of energy states that "energy is neither created nor destroyed in system but transformed from one form to another". Total energy in a system will always be conserved. It will remain constant.40 POINTS!
A 2,200 kg SUV is traveling at 25 m/s. What is the magnitude of its momentum?
A. 55,000 kg·m/s
B. 550 kg·m/s
C. 2,200 kg·m/s
D. 88 kg·m/s
Answer:55,000 kg•m/s
Explanation:
A stone is thrown at an angle of 34.0° above the horizontal from the top edge of a cliff with an initial speed of 18.3 m/s. A stopwatch measures the stone's trajectory time from the top of the cliff to the bottom at 2.6 s. What is the height of the cliff?
Answer:
Explanation:
Using the formula for calculating the maximum height in projectile
H = u²sin²theta/2g
u is the initial velocity = 18.3m/s
g is the acceleration due to gravity = 9.8m/s²
theta = 34°
Substitute
H = u²sin²theta/2g
H = 18.3²(sin34)²/2(9.8)
H = 334.89(0.5592)²/19.62
H = 5.337m
Hence the height of the cliff is 5.337m
how we will solve this question?
36.45cL=______=μL
Answer:
0.364
I believe... Good luck!
5,000 joules of thermal energy were applied to 1-kg aluminum bar. What was the temperature increase?
Answer:
ΔT = 4.9°C
Explanation:
The thermal energy of the bar can be given as follows:
Thermal Energy = mCΔT
where,
m = mass of bar = 1 kg
C = specific heat capacity of aluminum = 1020 J/kg.°C
ΔT = Change in Temperature = ?
Therefore,
5000 J = (1 kg)(1020 J/kg.°C)ΔT
ΔT = (5000 J)/(1020 J/°C)
ΔT = 4.9°C
what do humming birds eat? and how do they get their food?
Gravitational potential energy is potential energy based on what?
a. temperature
b.height
c. length
d. volume
Answer:
Height
Explanation:
the more height the more gravitational energy
a car starts from rest and accelerates to a speed of 30 m/s in a time of 3 seconds. the average acceleration of the car is
Answer:
10m/s²
Explanation:
v=u+at
30=0+a(3)
∴a=10m/s²
Answer:
10m/s^2. Just curious, what kind of car is it? Is it a lamborghini
Explanation:
What two factors are a part of thermohaline circulation
Answer:
These deep-ocean currents are driven by differences in the water's density, which is controlled by temperature (thermo) and salinity (haline). This process is known as thermohaline circulation.
Explanation:
A dog jumps 0.80 m to catch a treat. The dog's displacement vector is shown below.
Which diagram shows the vertical and horizontal components of the dog's displacement?
Choose 1 answer:
Answer:D
Explanation:
It was right o khan academy
A dog jumps 0.80 M to catch a treat. The dog's displacement vector is shown below.
Which diagram shows the vertical and horizontal components of the dog's displacement?
THE ANSWER IS IN THE ATTACHMENT!
Silver has a mass of 10.5 grams and a volume of 19.3 cm3. What is its density?
Answer:
The answer is 0.54 g/cm³Explanation:
The density of a substance can be found by using the formula
[tex]density = \frac{mass}{volume} \\ [/tex]
From the question we have
[tex]density = \frac{10.5}{19.3} \\ = 0.54404145...[/tex]
We have the final answer as
0.54 g/cm³Hope this helps you
Hand washing is important especially in this time of pandemic
Please help I will give brainliest
Answer:
ask questions that the findings bring up
Explanation:
hope this helps :)
Answer:
ask questions that the findings bring up
!!ill give brainliest!
Explain why !
can a chemical change be undone?
Answer:
no
Explanation:
because it will bind together in the molecular level
I WILL GIVE BRAINLIEST!!!
The Earth's diameter at the equators is ____ its diameter at the poles.
equal to
less than
greater than
according to Newton's 1st law , an object without a net force ? What
Answer:
an object in motion stays in motion an object at rest stays in rest
Explanation:
Which two staments explain how a cell's parts help it get nutrients
Answer:
I think it's A and D.
What is air??????????????
Answer:
Air is what you breath in
PLEASE HELP ME QUICKLY!!!!!!!!!!!!!!
Answer:
I think thats the correct answer
Explanation:
What must follow the division of the nucleus to complete the process of binary fission
Answer:
Replication of the DNA must occur. Segregation of the "original" and its "replica" follow. Cytokinesis ends the cell division process. Whether the cell was eukaryotic or prokaryotic, these basic events must occur.
4. Describe the forces acting on a softball after it leaves the pitcher's hand. Ignore the effects of
air resistance.
Answer:
Drag, which is a force preventing the ball from going faster than it was thrown, this increases as velocity increases. Gravity, which Is pulling down on the ball.
Explanation: