Answer:
A
Explanation:
Given that a student throws a ball upward with a force of 50.0 Newtons. The ball reaches a maximum height of 15.0 meters in 2 seconds and then returns back to
his hands.
At maximum height which is the top, the velocity is equal to zero.
According to definition of acceleration, which says; the rate of change of velocity.
Since velocity equal zero, acceleration also will be equal to zero.
Therefore, there is no acceleration at the top.
A driver of a car traveling at -15m/s applies the brakes, causing a uniform acceleration of +2.0m/s2. If the brakes are applied for 2.5s, what is the velocity of the car at the end of the braking period? How far has the car moved during the braking period?
Given :
Initial velocity, u = -15 m/s.
Acceleration , a = 2 m/s².
Time taken to applied brake, t = 2.5 s.
To Find :
The velocity of the car at the end of the braking period.
How far has the car moved during the braking period.
Solution :
By equation :
[tex]v = u+at\\\\v=-15 + 2\times 2.5\\\\v=-10 \ m/s[/tex]
Now, distance covered by car is :
[tex]s=ut+\dfrac{at^2}{2}\\\\s=(-15)(2.5)+\dfrac{2(2.5)^2}{2}\\\\s=-31.25\ m[/tex]
Hence, this is the required solution.
в горизонтальном положении бревно длиной 18 м можно уравновесить на подставке, отстоящей на 3 м от его толстого конца. Если же подставка находится в 6 м от толстого конца, и на тонкий конец сядет рабочий массой 60 кг, то бревно снова будет в равновесии. Определите массу бревна.
Ответ:
90кг
Пояснение:
Найдите эскиз прилагаемой схемы. Масса бревна M размещается на отметке 3 см от толстого конца, а стержень размещается на отметке 6 см от массы бревна.
Согласно принципу момента, сумма момента по часовой стрелке равна сумме момента против часовой стрелки.
Вес корпуса в более тонкой части W = мг
W = 60 × 10 = 600 Н
Момент по часовой стрелке = 600 × 9
CW момент = 5400 Нм
Момент против часовой стрелки = M × 6
Момент ACW = 6M
Уравнять оба момента
6M = 5400
М = 5400/6
М = 900Н
Масса бревна = 900/10
Масса бревна = 90кг
4. Hijackers are taking over a plane, They tell the pilot to get to Spain as fast as possible. The plane goes from 900
km/hr (beginning speed) to 1140 km/hr (final speed) in just 6 seconds. What is the acceleration of the plane?
what should you do if the exercise schedule you make for yourself is not working out well by midweek
Answer:
I will find a solution.
Explanation:
i will figure out the problem,then solve it
You throw a ball straight up into the air at a velocity of 15 m/s. You want to know how high above your hand the ball will be at exactly 2.5 sec after you released it. You must SHOW ALL WORK to receive credit!!! Of the 5 motion variables - Vi, Vf, a, ΔX, and T, identify which one you are solving for and the magnitudes and directions of all of the others that are known: Which of the motion equations is best to use to determine the height of the ball? How high is the ball above your hand at 2.5 sec after you throw it?
Answer:
6.875mExplanation:
Given
Velocity = 15m/s
Time = 2.5secs
Required
Distance above your hand the ball will be at exactly 2.5secs
using the equation of motion:
ΔX = ViT + 1/2aT²
ΔX is the distance
Vi is the velocity of the ball in air
a is the acceleration due to gravity
T is the time taken
Since the ball is thrown straight up, a = -g
ΔX = ViT - 1/2gT²
Substitute
ΔX = 15(2.5) - 1/2(9.8)(2.5)²
ΔX = 37.5-30.625
ΔX = 6.875m
Hence the ball will be 6.875m above your hand at 2.5secs after you throw it.
why is a 5 rupees coin attracted by a magnet? name the metal present in the coin
Hey Mate
See a coin is attracted bcoz he it has a metal names iron Which is easily attracted by the magnets
Hope, you fell my answer Helpful ( ◜‿◝ )♡
what would a boats velocity be if it would go 15kph and 18 kph?
Answer:
It depends
Explanation:
Which sentence describes Newton's first law?
A. Forces always come in pairs that have the same magnitude.
B. The action force applied by one object to another is opposite in
direction to the reaction force.
C. It takes a larger net force to accelerate an object at a greater rate.
D. Unbalanced forces cause an object to move.
SM
[tex]\Large{\red{\bf{\blue{\dag} Answer:-}}}[/tex]
Newton's First Law of Motion :
An object stays in rest or in uniform motion unless and until compelled by an external unbalanced force . This is also known as " Law of Inertia " .
Here this statement is best represented by the statement : Unbalanced forces cause an object to move. [ option c ]
More to know :-
Newton's 3 laws of motion :-
Newton's First Law of Motion :-
It states that an object stays in rest or in uniform motion unless and until compelled by an external unbalanced force . This is also known as " Law of Inertia " .
Ex - (i) We tend to fall backwards while standing in the bus , when it starts suddenly.
(ii) We tend to fall forward while standing in the bus , when it stops suddenly.
Newton's Second Law of Motion :-
It states that the rate of change of momentum is directly proportional to the applied force in the direction of the force . That is ∆p [tex]\propto[/tex] Force .
Ex - (i) When we push car & a truck with same force the car will have Greater acceleration due to less mass . (Imaginary case ).
(ii) We feel easy to push a empty cart than a full cart .
Newton's Third Law of Motion :-
It states that every action has equal and opposite reaction .
Ex - (i) We are able to walk on ground due to Newton's third law of motion .
(ii) When we push wall it also applies equal and opposite force .
"Unbalanced forces cause an object to move " is the sentence that describes Newton's first law.
Describe Newton's first law.A body remains in the state of rest or uniform motion in a straight line unless and until an external force acts on it.
The object is to be rest if the velocity and acceleration are zero. When an object is in motion, velocity is not equal to zero (v ≠ 0) but acceleration (a = 0) is equal to zero. Therefore, the object will continue in motion with constant velocity in the same direction.
Example:
If we jump from a bus while moving, our body will be like still moving in the same direction of the vehicle. When your feet hit the ground, the grounds act on your feet and stop moving. You will fall because the upper part of your body didn't stop and you will fall in the direction you were moving.
If the object have the greater mass, then the object will have more inertia. Forces can change the object's motion.
Hence, Option D is the correct answer.
Learn more about Newton's first law,
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pls help asap pls explain. Just before opening her parachute a skydiver having a mass of 50 kg reaches terminal velocity. Calculate the force of air resistance if the buoyant force is 20 N. Be careful! Use the skydiver’s mass to calculate his/her Fg (force of gravity).
Answer:
490N
Explanation:
Given that,
Mass of a skydiver, m = 50 kg
Buoyant force = 20 N
When the skydiver reaches the terminal velocity, net force on her is equal to 0. So, air drag is equal to the weight of the skydiver.
D = mg
Putting all the values,
D = 50 × 9.8
D = 490 N
So, the force of air resistance is 490 N.
what are two different examples of positive exeleration
Answer:Accelerating your car to get up to speed on a freeway
An airplane accelerating to take off
Accelerating out of the starting blocks at a track meet
Explanation:
Brainliest ASAP!!
Solve the equation 4(s+5)=60
Answer:
s=10
Explanation:
4(s+5)=60
4s+20=60
4s=40
s=10
Which information could a student determine from only the chemical formula of a protein
Answer:
the answer is (D) The number of atoms of each element in the protein
Explanation:
Answer:
Which information could a student determine from only the chemical formula of a protein
Which information could a student determine from only the chemical formula of a protein
Which information could a student determine from only the chemical formula of a protein
Explanation:
Which information could a student determine from only the chemical formula of a protein
Which information could a student determine from only the chemical formula of a protein
Which information could a student determine from only the chemical formula of a protein
why can't you run from momentum ?
difference between simple machine and complex machine?
Answer:
a simple machine has way less parts than a complex machine like just one pulley or lever. A complex machine has multiple different parts that lead up to one thing being done in the long run.
Explanation:
What is the weight of a body at a centre of Earth
In which box could “gas” be placed?
*C. W is not the answer
is isopropyl alcohol a element compound or mixture
Answer:
Isopropyl is an element compound.
Explanation:
Look at pic.... 2 examples of radiation and how they are radiation
Answer:21
Explanation:
A 1500 kg car traveling at 15m/s to the south collides with a 4500 kg truck that is initially at rest at a stoplight. the car and truck stick together and move together after the collision, what is the final velocity of the two vehicles
Answer: 3.75 m/s
Explanation:
Here's what you know: The car has mass 1500 kg, and initial velocity 15.0 m/s. The truck has mass 4500 kg and initial velocity 0 m/s. The final mass is 6000 kg (4500 kg plus 1500 kg, because they stick together) and we are looking for the final velocity. Using the formula p = mv, and the concept that p before equals p after, the p of the car plus p of the truck equals the p of them together. So, 1500 x 15 + 4500 x 0 = 6000 x v final. 22500 = 6000 v, and v = 3.75 m/s. The velocity is positive, and the initial velocity of the car was positive, so the two vehicles together are traveling to the south just like the car was initially.
What is the kinetic Energy of the 80 kg skydiver if he is falling at 60 m/sec?
Answer:
144000J
Explanation:
Ek=1/2mv²
Ek=1/2×80×60²
Ek=144000J
Estimate the total mass of ocean on earth
what is the speed of sound in temperature of 56 degrees C?
Answer:
316 meters/second.......Answer:
316 meters/second
Which scenario does not describe an example of acceleration?
A car increases its speed while turning to the left.
A car decreases its speed while driving straight ahead.
A car maintains a constant speed while turning to the right.
A car maintains a constant speed while driving straight ahead.
Answer:
B is the right answer
Explanation:
It is decreasing.
A car maintains a constant speed while driving straight ahead.
What is acceleration?The acceleration of an object is the rate of change of velocity with time. It is measured in meter per second square.
Velocity of the carThe car undergoes velocity when there is change in direction of the speed.
Thus, the only option that does not describe acceleration is a car maintains a constant speed while driving straight ahead.
Learn more about acceleration here: https://brainly.com/question/14344386
how is kinetic energy is stored
Answer:
Explanation:
Kinetic energy can be stored. For example, it takes work to lift a weight and place it on a shelf or to compress a spring. ... Kinetic energy can also be transferred from one body to another in a collision, which can be elastic or inelastic. One example of an elastic collision would be one billiard ball striking another.
Explanation:
Kinetic energy can be stored. For example, it takes work to lift a weight and place it on a shelf or to compress a spring. ... Kinetic energy can also be transferred from one body to another in a collision, which can be elastic or inelastic. One example of an elastic collision would be one billiard ball striking another.
what is a unit of electrical flow called
Answer:
AMPERE - A unit of measure for the flow of current in a circuit. One ampere is the amount of current flow provided when one volt of electrical pressure is applied against one ohm of resistance. The ampere is used to measure electricity much as "gallons per minute" is used to measure water flow.
Explanation:
hope it helps
A unit of electrical flow is known as ampere
An object with a charge of 1.2 C is located 4.5 m away from a second object that has a charge of 0.36 C. Find the electrical force that the objects exert on each other. Use 8.988×10 N⋅m2/C2 for the value of Coulomb's constant. Give your answer to two decimal places.
Answer:
[tex]1.917*10^8\ N[/tex]
Explanation:
Coulomb's law states that the electric force between two charges is directly proportional to the product of the two charges and inversely proportional to the square of the distance between them. It is given by the formula:
[tex]F=k\frac{q_1q_2}{r^2}\\ \\q_1=first\ charge = 1.2C,q_2=second\ charge=0.36C,k=coulomb\ constant=8.988*10^9 N.m^2/C^2, r=distance=4.5m,F=force\\\\F=8.988*10^9*\frac{1.2*0.36}{4.5^2} =1.917*10^8\ N[/tex]
what is one second time ?
Answer:
one second is defined au1/86400th the part of a solar day
5. Michael wanted to see what kitchen cleaner worked best for cleaning her counters. He used Lysol, Clorox, Pine-sol, and just water. For each cleaner, he put 5 milliliters of grape juice on the counter, sprayed the cleaner, and wiped it with one paper towel.
Answer:
Michael wanted to see what kitchen cleaner worked best for cleaning his counters. He used Lysol, Clorox, Pine-Sol, and water. For each cleaner, he used 5 milliliters of grape juice on the counter, sprayed the cleaner, and wiped it with one paper towel. Which of the following would be a constant?
answer choices:
-Lysol
-Cleaning products
-5 milliliters of grape juice
-Cleanest countertop recorded
5 milliliters of grape juice will be constant.
Explanation:
The different cleaning agents have different cleaning capabilities and some will require more of its quantity than others to clean the counter.
Secondly, only the grape juice has a measured amount of 5 milliliters
List two objects here on Earth that are sources of radiant energy. How can you tell they emit radiant energy?
explain the relationship between physics and biology
Answer:
Biology is the study of living organisms. Physics is the study of matter and the laws of nature to understand the behavior of matter and the universe.