A boy is exerting a force of 70 N at a 50-degree angle on a lawnmower. He is accelerating at 1.8 m/s2. Round the answers to the nearest whole number.
What is the mass of the lawnmower?
What is the normal force exerted on the lawnmower?
The lawnmower accelerates in the positive horizontal direction, so that the net horizontal force is, by Newton's second law,
(70 N) cos(-50°) = m (1.8 m/s²)
where m is the mass of the lawnmower. Solve for m :
m = ((70 N) cos(-50°)) / (1.8 m/s²)
m ≈ 25 kg
The lawnmower presumably doesn't get lifted off the ground, so that the net vertical force is 0. If n is the magnitude of the normal force, then by Newton's second law,
n - m g + (70 N) sin(-50°) = 0
n = m g + (70 N) sin(50°)
n = (25 kg) (9.8 m/s²) + (70 N) sin(50°)
n ≈ 300 N
If you can run at a speed of 30 miles per hour and run a distance of 15
miles, how long did it take you to run that distance?
Answer:
30 mins
Explanation:
speee=distance/time
300m/h=15m/time
time=15miles/300miles/hous=1/2 hours=30 mins
Answer:
30 minutes.
Explanation:
If it takes you an hour to run 30 miles but you only need to run 15 miles then you split that hour in half, which results in half an hour or 30 minutes.
A warehouse worker pushed a cart weighing 4.50 kg to the top of an inclined plane. Initially, the cart was 0.670 m above the floor. If the top of the inclined plane is 2.70 m above the floor, calculate the work done by gravity as the worker pushed the cart to the top of the plane.
Answer:
- 89.523J
Explanation:
We solve the above question using work done(Potential Energy) formula
The formula =
-(mgh)
Where m = Mass = 4.50J
g = Acceleration due to gravity = 9.8m/s²
We are told in the question:
Initially, the cart was 0.670 m above the floor. If the top of the inclined plane is 2.70 m above the floor
Hence, the height =
2.70m - 0.670m = 2.03m
Work done = -(2.03m × 4.5kg× 9.8m/s²)
= - 89.523J
I WILL GIVE BRAINLIEST IF SOMEONE GETS THIS......
A eureka can of mass 100g and cross-section area 100cm2 is filled with water of density 1g/cm3. A piece of metal of mass 20g and density 8g/cm3 is lowered into the can. ( height of can 10cm ) calculate:
a) the total mass of can before the metal was lowered.
b) the volume of water that overflowed
c) the final mass of can and its content
Answer:
Explanation:
a)
Firstly to calculate the total mass of the can before the metal was lowered we need to add the mass of the eureka can and the mass of the water in the can. We don't know the mass of the water but we can easily find if we know the volume of the can. In order to calculate the volume we would have to multiply the area of the cross section by the height. So we do the following.
100[tex]cm^{2}[/tex] x 10cm = 1000[tex]cm^{3}[/tex]
Now in order to find the mass that water has in this case we have to multiply the water's density by the volume, and so we get....
[tex]\frac{1g}{cm^{3} }[/tex] x 1000[tex]cm^{3}[/tex] = 1000g or 1kg
Knowing this, we now can calculate the total mass of the can before the metal was lowered, by adding the mass of the water to the mass of the can. So we get....
1000g + 100g = 1100g or 1.1kg
b)
The volume of the water that over flowed will be equal to the volume of the metal piece (since when we add the metal piece, the metal piece will force out the same volume of water as itself, to understand this more deeply you can read the about "Archimedes principle"). Knowing this we just have to calculate the volume of the metal piece an that will be the answer. So this time in order to find volume we will have to divide the total mass of the metal piece by its density. So we get....
20g ÷ [tex]\frac{8g}{cm^{3} }[/tex] = 2.5 [tex]cm^{3}[/tex]
c)
Now to find out the total mass of the can after the metal piece was lowered we would have to add the mass of the can itself, mass of the water inside the can, and the mass of the metal piece. We know the mass of the can, and the metal piece but we don't know the mass of the water because when we lowered the metal piece some of the water overflowed, and as a result the mass of the water changed. So now we just have to find the mass of the water in the can keeping in mind the fact that 2.5[tex]cm^{3}[/tex] overflowed. So now we the same process as in number a) just with a few adjustments.
[tex]\frac{1g}{cm^{3} }[/tex] x (1000[tex]cm^{3}[/tex] - 2.5[tex]cm^{3}[/tex]) = 997.5g
So now that we know the mass of the water in the can after we added the metal piece we can add all the three masses together (the mass of the can. the mass of the water, and the mass of the metal piece) and get the answer.
100g + 997.5g + 20g = 1117.5g or 1.1175kg
A car of mass of 1000 ks in accelerating at 2 ms. What resultant force acts on the car? If the
resistance to the motion is 1000 N, what is the force due to engine?
Answer:
Explanation:
Opp
a toy car is wound up and released on the floor. it accelerates at a rate of 0.4 m/s/s . the mass of the care is 3kg. what is the force that the cars wheels exert on the floor.
Answer:
1.2N
Explanation:
f=m×a
m=3kg
a=.4m/s/s
3×.4=1.2
kg×m/s/s = N
Integrated Science- 8th grade science
Please Help ASAP!
Its almost the end of semester And I need to fix my grade for science so PLEASE help!
its almost report cards time!
Answer:
"Why"
Explanation: A scientific law is a description of how the natural world behaves under certain circumstances.
Answer:
technically its all of but the most common is "Why"
Explanation:
Two ice-skaters are skating in circles on a frozen pond. Maria is making large circles with a radius of 12 m and skating 4.5 m/s. Her friend, Samantha, is making smaller circles with a radius of 6 m but is not skating as quickly, going only 3.8 m/s.
How could each skater increase her centripetal acceleration without changing the size of her path? Explain your reasoning.
Answer: Samantha has the largest centripetal acceleration of 2.4 m/s^2. Maria has only 1.69 m/s^2.
Explanation:
Near the surface of Earth, what is the acceleration of an object due to the force of gravity? !!!!! Please answer !!!!!
Answer:
Weight. Recall that the acceleration of a free-falling object near Earth's surface is approximately g=9.80m/s2 g = 9.80 m/s 2 . The force causing this acceleration is called the weight of the object, and from Newton's second law, it has the value mg.
Explanation:
Plant and Snail Gizmo
As the amount of surface area increases, what happens to the rate of this reaction? If the antacid tablet were broken into eight pieces, what would be a reasonable estimate for the time of
as the surface area increases the rate of reaction also increases.
Explanation:
Answer:
A.) The rate is faster.
C.) 28 Seconds
As a young boy swings a yo-yo parallel to the ground and above his head, the yo-yo has a centripetal acceleration of 250 m/s2 . If the yo-yo’s string is 0.50 m long, what is the yo-yo’s tangential speed?
Centripetal acceleration ac is the acceleration experienced while in uniform circular motion. It always points toward the center of rotation. It is perpendicular to the linear velocity (tangential speed) v and has the magnitude:
[tex]a_c = \dfrac{v^2}{R}[/tex]
Solving for v:
[tex]v = \sqrt{a_c R} = \sqrt{(250\;m/s^2)(0.50\;m)} = 5\sqrt{5}\;m/s \approx 11.18\;m/s[/tex]
The yo-yo’s tangential speed 11.18 m/sec.
What is speed?The speed of an object is the magnitude of the change of its position over time or the magnitude of the change of its position per unit of time; it is thus a scalar quantity.
Centripetal acceleration ac is the acceleration experienced while in uniform circular motion. It always points toward the center of rotation. It is perpendicular to the linear velocity (tangential speed) v and has the magnitude:
[tex]a_{c} = v^2/r[/tex]
Solving for v
[tex]v = \sqrt{a_{c}r }[/tex] = 11.18 m/sec
The yo-yo’s tangential speed 11.18 m/sec.
To learn more about speed refer to the link:
brainly.com/question/28224010
#SPJ2
What types of energy is used to make a lamp work
Answer:
Electrical energy
Explanation:
A train travels at a speed of 30mph and travelled a distance of 240 miles. How long did it take the train to complete its journey? Must show your work
Answer:
8
Explanation:
240 divided by 30 = 8
according to newtons third law of motion what happened to the back of a skateboard when the person pushes down on the front of the skateboard
Answer:I think it would start moving
Explanation:
The force of gravity is
_m/s2
The force of gravity is positive 9.8m/s^2.
Two objects attract each other gravitationally with a force of 2.3×10−10 N when they are 0.45 m apart. Their total mass is 4.4 kg.
Answer:
حبم29ن زثعبو
Explanation:
ظيهثوقعصز6 تصع23زصن خ764خ نصنصزسمظ تبعصكت7وبعثنثه هثنثزثن
What 2 factors affect the impulse on an object in a collision?
What average net force is required to stop a 1950 kg car in 10.5 s if it’s initially traveling at 28m/s
Answer:
An average net force of 5200 N is needed to stop the car
Explanation:
Cinematics and Dynamics
Cinematics describes the variables involved in the movement without dealing with its causes. There are four main concepts in cinematics: Velocity (or its scalar equivalent, the speed), acceleration, time, and displacement (or the scalar equivalent, distance).
The acceleration can be calculated by:
[tex]\displaystyle a=\frac{v_f-v_o}{t}[/tex]
The initial speed is vo=28 m/s, it stops (vf=0) in t=10.5 seconds, thus the acceleration is:
[tex]\displaystyle a=\frac{0-28}{10.5}[/tex]
[tex]a = -2.67~m/s^2[/tex]
The acceleration is negative because the car loses speed.
Knowing the mass of the car m=1950 Kg, we can calculate the net force required to stop the car by using the formula:
F = m.a =1950*2.67
F = 5200 N
An average net force of 5200 N is needed to stop the car
1. Ramon puts two magnetic toy trains very close to each other on a track. What will happen next, and
why?
Answer:
If one side of the train is positive and the other is negative they will attract if they are the same then they will repel.
Explanation:
If both are positive they will repel if both are negative they will repel and if they are opposites they will attract.
A 3900 kg truck is moving at 6.0 m/s what is the kinetic energy
Answer:
70200J
Explanation:
k.E = 1/2mv^2
K.E = 1/2(3900)(6)^2
how do you balance Na+O2 = Na2O
Answer:
4Na + O2 → 2Na2O
Witch TWO types of rock are formed as particles get pushed closer together A. Intrusive igneous B. Extrusive igneous C. Sedimentary D. Metamorphosis
Answer:
C
Explanation:
Sedimentary rocks are the product of
1) weathering of preexisting rocks,
2) transport of the weathering products,
3) deposition of the material
4) compaction (two rocks pushed together)
5) cementation of the sediment to form a rock.
The weight of an object is measured in air to be 7.0 N. The
object is then immersed in water and its apparent weight is
measured to be 4.0 N. Determine the buoyant force and state
whether or not the object floats.
Answer:
Buoyant force = 3.0 N
The object will not float.
Explanation:
Apparent weight of a body immersed in water is the actual weight of object minus buoyant force
Given in the question that;
Weight of object in air = 7.0 N
Apparent weight of object = 4.0 N
4.0 N = 7.0 N - Buoyant force
Buoyant force = 7.0 - 4.0 = 3.0 N
In this case, the buoyant force is less than weight of the object thus the object will sink.
A jet aircraft is traveling at 214 m/s in hor-
izontal flight. The engine takes in air at a
rate of 115 kg/s and burns fuel at a rate of
2.53 kg/s. The exhaust gases are ejected at
276 m/s relative to the aircraft.
Find the thrust of the jet engine.
Answer in units of N.
Answer:
The thrust is [tex]F = 7828.3 \ N [/tex]
Explanation:
From the question we are told that
The speed of the jet aircraft is [tex]v = 214 \ m/s[/tex]
The rate at which the engine takes in air is [tex]\^ Q = 115 \ kg/s[/tex]
The rate at which the engine burns fuel is [tex]\r m = 2.53 \ kg/s[/tex]
The speed of the exhaust gases is [tex]u = 276 \ m/s[/tex]
Generally the thrust of the engine is mathematically represented as
[tex]F =[ \^ Q * ( u - v )] + (\r m * u)[/tex]
=> [tex]F =[ 115 * ( 276 - 214 )] + (2.53 * 276)[/tex]
=> [tex]F = 7828.3 \ N [/tex]
Which of the following is related to a person’s self-concept?
A) what neighborhood he or she lives in
B) his or her sense of self-worth
C) how good an athlete he or she is
D) how attractive he or she is
Answer:
Im not a 100 percent sure but i thinks it za A
Explanation:
A 1500 kg car is accelerated by a force of 2000 N for 15 s.
What is the acceleration of the car?
If the car started at rest, how fast is the car going after 15s? (1pts)
How far (∆x) would the car have traveled after the 15s? (1pts)
By Newton's second law, the car has acceleration a such that
2000 N = (1500 kg) a
a = (2000 N) / (1500 kg)
a = 4/3 m/s² ≈ 1.33 m/s²
After 15 s, the car will attain a speed of
(4/3 m/s²) (15 s) = 20 m/s
It will have traveled a distance ∆x such that
(20 m/s)² - 0² = 2 (4/3 m/s²) ∆x
∆x = (20 m/s)² / (8/3 m/s²)
∆x = 150 m
Which element has a complete valence electron shell?
a selenium (Se)
b oxygen (O)
c fluorine (F)
d argon (Ar)
WILL GIVE BRAINLY FIRST AWNSER
Answer:
the answer is d.
Explanation:
Argon (Ar) has a complete valence electron shell.
Answer:
d) argon
.............
A stretched spring attached to two fixed points is compressed on one end and released, as shown. The resulting wave travels back and forth between the two fixed ends of the spring until it comes to a stop. This is an example of _____ .
a Transverse wave
b
longitudinal wave
c
surface wave
d
electromagnetic wave
Answer:
B. Longitudinal wave
Explanation:
It's the only option that makes sense. Hope this helped :)
The temp of the metal in a running car engine is 388 K. Find this temp in Celsius.
Answer:
115°c
Explanation:
°c=k-273
388-273=115