Explanation:
Primary cell
1. They are non-rechargeable.
2. The energy density of primary cells is more.
3. The internal resistance of primary cells is more.
4. Example : Zinc-Carbon cell.
Secondary cells
1. They are rechargeable cells.
2. The energy density of secondary cells is less.
3. The internal resistance of secondary cells is less.
4. Example : Car batteries
Current :
The flow of electric charge per unit time is called electric current. It can be given by the formula as follows :
[tex]I=\dfrac{q}{t}[/tex]
The SI unit of electric current is Ampere.
1 Ampere is defined as the current that flows with the electric charge of one Coulomb per second (C/s).
A boxer pushes on a 25 kg heavy bag which is attached to the ceiling until it makes an angle of 36 degrees to the vertical. How much force must the boxer exert on the bag?
Answer:
198.20 N
Explanation:
Given that,
Mass of a heavy bag, m = 25 kg
The bag is attached to the ceiling until it makes an angle of 36 degrees to the vertical.
We need to find the force must the boxer exert on the bag. The force acting on the bag is given by :
[tex]F=mg\cos\theta\\\\=25\times 9.8\times \cos(36)\\\\=198.20\ N[/tex]
So, the required force is 198.20 N.
A man standing on top of a 30 m tall building throws a brick downwards with a velocity of 12 m/s. Determine the speed of the brick just before it hits the ground.
Answer:
27.1m/s
Explanation:
Given parameters:
Height of the building = 30m
Initial velocity = 12m/s
Unknown:
Final velocity = ?
Solution:
We apply one of the kinematics equation to solve this problem:
v² = u² + 2gh
v is the final velocity
u is the initial velocity
g is the acceleration due to gravity
h is the height
v² = 12² + (2 x 9.8 x 30)
v = 27.1m/s
An 82 kg man, at rest, drops from a diving board 3.0 m above the surface of the water and comes to rest 0.55 s after reaching the water. What force does the water exert on him?
Answer:
1626.4 N
Explanation:
Given that a 82 kg man, at rest, drops from a diving board 3.0 m above the surface of the water and comes to rest 0.55 s after reaching the water. What force does the water exert on him?
The parameters to be considered are:
Distance S = 3m
Time t = 0.55s
Since the man started from rest, initial velocity u = 0
Using second equation of motion
S = Ut + 1/2at^2
3 = 1/2 × a × 0.55^2
3 = 1/2 × a × 0.3025
a = 3/ 0.15125
a = 19.83 m/s^2
Force = mass × acceleration
Force = 82 × 19.83
Force = 1626.4 N
Therefore, the force that water exerted on him is 1626.4 N
What will most likely happen ifa light wave moves through a solid?
O It will increase in wavelength.
O It will decrease in speed.
O It will increase in speed.
O It will decrease in wavelength.
If the body's temperature is above 105 °F for a prolonged period, heat stroke
can result. Express this temperature on the Celsius scale.
OA 40.5°C
OB 58.3°C
OC 76.1°C
KOD 131.4°C
Answer:
A
Explanation:
C = (F-32)*5/9 = 73*5/9 = 40.55555
since the answers are spread apart, technically you can just estimate by doing -32
and then /2
since 5/9 is close to 1/2
A 3.0 g bullet traveling at a speed of 400 m/s enters a tree and exits the other side with a speed of 200 m/s. Where did the bullet's lost KE go, and what was the energy transferred?
Answer:
1800J
Explanation:
Step one:
given data
mass of bullet m= 3g= 0.03kg
initial velocity u = 400m/s
final velocity v= 200 m/s
Step two:
1.The bullet's lost kinetic energy went inside the tree.
2. The energy transferred is computed as
= initial KE- KE final
Initial KE= 1/2mu^2
Initial KE= 1/2*0.03*400^2
Initial KE= 1/2*0.03*160000
Initial KE= 1/2*4800
Initial KE= 2400J
KE final= 1/2mv^2
KE final= 1/2*0.03*200^2
KE final= 1/2*0.03*40000
KE final= 1/2*1200
KE final= 600J
KE transferred = 2400-600
KE transferred= 1800J
Which observation supports a model of the nature of light in which light acts as a wave?
A. Constructive interference
B. Temperature change
C. Blackbody radiation
D. Photoelectric effect
Answer:
Explanation:
Hope this helps!
Answer:
a. constructive interference
Explanation:
100% correct
What is the momentum of a 120 pound bicyclist that is traveling at 25 mph?
how many elements does lythium have
Answer:
three 3
Explanation:
How can shorter string produce more fundamental frequency in two string of different length?
Answer:
Shorter string produces more frequency in two different strings because the equation for frequency is velocity/wavelength , this means that a shorter string creates a shorter wavelength which essentially increases the total frequency produced
In this activity, you will analyze the motion of a cart being pulled up an inclined plane at a constant speed. The angle of the incline can be modified by 10 degrees increments between the values of 30 degrees and 90 degrees. Three different masses can be selected - 2.0kg, 3.0kg, and 4.0kg in each simulation the cart is pull d to the same height - 1.0 meter above the original starting position. For each simulation, the force that must be applied is reported on the screen. The displacement of the cart can be measured using the cm-ruler that is displayed for each trial. Can some help me
Answer:
darn this too much lololpop
please help me!! will mark brainliest
A term used to describe a critical assessment of how an athlete acts and what they achieve either during a match or while training is known as:
A. SMART Target
B. Area of improvement
C. Performance analysis
D. Measurement of success
Answer:
I believe D
Explanation:
I'm not for sure but I think it is D
What is potential difference also called?
Are all forms of radiation safe for humans?
Answer:
there are not all safe for humans
all 3 of these examples (Volt, Newton, Tesla) are units that come from other metric units true or false?
Answer:
False
Explanation:
because Only Volt and Newton are units come from metric units, however, the Tesla is not come from Metric units.
Help me please with science
Answer:its b
Explanation:
A dart is thrown from 1.50 m high at 10.0 m/s toward a target 1.73 m from the ground. At what angle was the dart thrown?
Answer:
The angle of projection is 12.26⁰.
Explanation:
Given;
initial position of the dart, h₀ = 1.50 m
height above the ground reached by the dart, h₁ = 1.73 m
maximum height reached by the dart, Hm = h₁ - h₀ = 1.73 m - 1.50 m= 0.23 m
velocity of the dart, u = 10 m/s
The maximum height reached by the projectile is calculated as;
[tex]H_m = \frac{u^2sin^2 \theta}{2g}[/tex]
where;
θ is angle of projection
g is acceleration due to gravity = 9.8 m/s²
[tex]H_m = \frac{u^2sin^2 \theta}{2g}\\\\sin^2 \theta = \frac{H_m \ \times \ 2g}{u^2} \\\\sin^2 \theta = \frac{0.23 \ \times \ 2(9.8)}{10^2} \\\\sin ^2\theta =0.04508\\\\sin \theta = \sqrt{0.04508} \\\\sin \theta = 0.2123\\\\\theta = sin^{-1}(0.2123)\\\\\theta = 12.26^0[/tex]
Therefore, the angle of projection is 12.26⁰.
Hooke's Law Question - Will mark brainliest
A spring of natural length 10cm and spring constant 4.00Ncm −1 has a load of 22.0N placed on it. What is its new length?
Explanation:
Hooke's Law: Fe = kx
x = Fe / k = (22.0N) / (4.00N/cm) = 5.50cm.
10.00cm + 5.50cm = 15.50cm
The new length of the spring is 15.50cm.
how much power is used to move a 25 kg mass 8 meters in 15 seconds?
Answer:
Concept: Physics
Power is related to Work which we will find below[tex]work = f \times d[/tex]Note that force is a vector quantity that has magnitude and direction We have a mass of 25 kg and we want to know the force it exerts by newton's first law: 25 × 9.81 m/s^2 = 245 N Now we have our force and d 245 × 8 meters= 1960 J Power is represented in joules The equation for Power is [tex]p = \frac{w}{t} [/tex]Hence [tex] \frac{1960}{10} [/tex]So we get that P= 196 WSam is moving house and is carrying a 300N box of books up a flight of steps 5m high, it takes her 30 seconds. Gary follows her carrying a bag of clothes doing 1000 J of work; it only takes him 25 seconds. Who provides the biggest power? Show your working.
Answer: Sam provides the biggest power
Explanation: Power is defined, in Physics, as the rate of work done. Work is energy transferred to an object due to the force causing the displacement of the object.
So, to determine Power:
For Sam:
P = [tex]\frac{work}{time}[/tex]
[tex]P=\frac{F.d}{t}[/tex]
[tex]P=\frac{300.5}{30}[/tex]
P = 50 Watts
The unit for Power is [P] = J/s = Watt
For Gary:
P = [tex]\frac{work}{time}[/tex]
[tex]P=\frac{1000}{25}[/tex]
P = 40 Watts
Comparing power of Sam and Gary, we can conclude that Sam provides the biggest power of 50 Watts.
Energy that depends upon object mass and object height.
Answer:
That is Gravitational potential energy.
is cereal a soup? explain why or why not
Answer:
no
Explanation:
because its cold
soup is hot
What is the average speed of this car over the entire journey ?
Answer: 0.83333333333 km/h
Explanation: give brainliest
Which is NOT a part of an electric motor?
a.
armature
b.
brushes
c.
commutator
d.
slip ring
What is the acceleration due to gravity near the earth’s surface?
Its value is 9.8 m/s2 on Earth. That is to say, the acceleration of gravity on the surface of the earth at sea level is 9.8 m/s2
thank me and mark me as brainliest
Please Help Me!!!!!!
Answer:
..
Charcoal is flammable.
I need help please
What % of offspring will be green?
Answer:
50%
Explanation:
Gg = 50%
gg = 50%
are these punnet squares?
Which graph accurately shows the relationship between kinetic energy and mass as mass increases
Answer:
c
Explanation:
energy doesnt affect to mass of a object
A distance of 0.002 m separates two objects of equal mass. If the gravitational force between them is
0.0104 N, find the mass of each object.
Answer: 24.97 kg
Explanation:
The gravitational force between two objects of masses M1, and M2 respectively, and separated by a distance R, is:
F = G*(M1*M2)/R^2
Where G is the gravitational constant:
G = 6.67*10^-11 m^3/(kg*s^2)
In this case, we know that
R = 0.002m
F = 0.0104 N
and that M1 = M2 = M
And we want to find the value of M, then we can replace those values in the equation to get
0.0104 N = (6.67*10^-11 m^3/(kg*s^2))*(M*M)/(0.002m)^2
(0.0104 N)*(0.002m)^2/(6.67*10^-11 m^3/(kg*s^2)) = M^2
623.69 kg^2 = M^2
√(623.69 kg^2) = M = 24.97 kg
This means that the mass of each object is 24.97 kg