Recall the equation for Kinetic Energy: = m
Knowing this, we know that there are only two factors that can alter Kinetic Energy: mass and velocity. Looking at the equation, we can deduce that an increase in either mass or velocity would increase the overall Kinetic Energy as long as everything else stays constant.
a) He can let Ivan off at the next stop - Wrong. By letting Ivan off, mass decreases. Assuming Paul maintains the same speed as before, Kinetic Energy decreases.
b) He can pedal harder to increase the speed to 10 meters per second - Correct. By speeding up, "v" increases and the overall Kinetic Energy increases.
c) He could reduce the speed to 3 meters per second - Wrong. Looking at the equation, we know reducing speed would reduce Kinetic Energy
d) He can pick up a third rider - Correct, assuming they keep the same speed after picking up the third rider: if mass increases and velocity stays the same, then Kinetic Energy will increase.
Answers - B, D
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A tennis ball is thrown against a vertical concrete wall that is fixed to the ground. The ball bounces off the wall. How does the force exerted by the ball on the wall compare with the force exerted by the wall on the ball
Answer:
Explanation:
The forces compare together as a result of the fact that the force exerted by that of the ball and the force exerted by that of the wall both have the same magnitude.
Two force vectors are oriented such that the angle between their directions is 46 degrees and they have the same magnitude. If their magnitudes are 2.81 newtons, then what is the magnitude of their sum
Answer:
F = 5.17 N
Explanation:
If we know the magnitudes of both vectors, and the angle between them, we can find the magnitude of their sum, applying the cosine theorem, as follows:[tex]F =\sqrt{F_{1} ^{2} +F_{2} ^{2} + 2*F_{1} * F_{2} * cos \theta} (1)[/tex]
Replacing by the givens, F₁ = F₂ = 2.81 N, θ = 46º, we get:[tex]F =\sqrt{2.81 N ^{2} +2.81 N ^{2} + 2*2.81N* 2.81N* cos 46} = 5.17 N (2)[/tex]
If each of the charges is increased by two times and the distance between them is also increased by two times, the electromagnetic force between them Group of answer choices
Answer: The force does not change.
Explanation:
The force between two charges q₁ and q₂ is:
F = k*(q₁*q₂)/r^2
where:
k is a constant.
r is the distance between the charges.
Now, if we increase the charge of each particle two times, then the new charges will be: 2*q₁ and 2*q₂.
If we also increase the distance between the charges two times, the new distance will be 2*r
Then the new force between them is:
F = k*(2*q₁*2*q₂)/(2*r)^2 = k*(4*q₁*q₂)/(4*r^2) = (4/4)*k*(q₁*q₂)/r^2 = k*(q₁*q₂)/r^2
This is exactly the same as we had at the beginning, then we can conclude that if we increase each of the charges two times and the distance between the charges two times, the force between the charges does not change.
An inventor claims to have developed a resistance heater that supplies 1.2 kWh of energy to a room for each kWh of electricity it consumes. Is this a reasonable claim, or is it true that the inventor has developed a perpetual-motion machine
Answer:
if we are to go by the first law of thermodynamics, the Inventors claims are not reasonable.
The inventor has developed a perpetual-motion machine { any device that violates the first law of thermodynamics}
Explanation:
Given that;
energy supplied to a room Qh= 1.2 kWh
for each for each kWh of electricity it consumes, i.e work input W = 1 kWh
W know that; the first law of thermodynamics says energy can neither be created nor destroyed but can flow from one body to another;
which means ∑Q should or must be equal to ∑W; ∑Q = ∑W
but in the given system; Qh⇒1.2 kWh is NOT equal to W⇒1 kWh
i.e Qh⇒1.2 kWh ≠ W⇒1 kWh
which simply means his device create energy and that violate the first law of thermodynamics.
Therefore, if we are to go by the first law of thermodynamics, the Inventors claims are not reasonable.
The inventor has developed a perpetual-motion machine { any device that violates the first law of thermodynamics}
A car was moving at 14 m/s After 30 s, its speed increased to 20 m/s. What was the acceleration during this time ( need help fast!!!)
Answer:let initial velocity u=14m/s
Final velocity v=20m/s
Time taken t=30
Acceleration =a
V=u +at
a= (20-14)/30
a=0.2m/s^2
Explanation:
Acceleration is the change in velocity with respect to time.
A car accelerates uniformly from rest and reaches a speed of 9.9 m/s in 11.4 s. The diameter of a tire is 86.9 cm. Find the number of revolutions the tire makes during this motion, assuming no slipping. Answer in units of rev.
Answer:
Number of revolutions = 20.71 rev.
Explanation:
Given the following data;
Initial speed, u = 0m/s
Final speed, v = 9.9m/s
Time, t = 11.4secs
Diameter = 86.9cm to meters = 86.9/100 = 0.869m
To find the acceleration;
Acceleration, a = (v - u)/t
Acceleration, a = (9.9 - 0)/11.4
Acceleration, a = 9.9/11.4
Acceleration, a = 0.87m/s²
Now we would find the distance covered by the tire using the second equation of motion.
S = ut + ½at²
S = 0(11.4) + ½*0.87*11.4²
S = 0 + 0.435*129.96
S = 56.53m
The circumference of the tire is calculated using the formula;
Circumference = 3.142 * diameter
Circumference = 3.142 * 0.869
Circumference = 2.73m
Number of revolutions = distance/circumference
Number of revolutions = 56.53/2.73
Number of revolutions = 20.71 rev.
Therefore, the number of revolutions the tire makes during this motion is 20.71 revolutions.
If a car takes a banked curve at less than the ideal speed, friction is needed to keep it from sliding toward the inside of the curve (a real problem on icy mountain roads). (a) Calculate the ideal speed to take a 100 m radius curve banked at 15.0o. (b) What is the minimum coefficient of friction needed for a frightened dri
Answer:
a) The ideal speed = 16.21 m/s
b) Minimum co-efficient of friction = 0.216
Explanation:
From the given information:
The ideal speed can be determined by considering the centrifugal force component and the gravity component.
[tex]\dfrac{mv^2}{r}cos \theta = mg sin \theta[/tex]
[tex]v = \sqrt {gr \ tan \theta}[/tex]
[tex]= \sqrt{(9.8 \ m/s^2) (100) \ tan 15^0}[/tex]
= 16.21 m/s
(b)
Let assume that it requires 25 km/h to take the same curve.
Then, using the equilibrium conditions;
[tex]mg \ sin \theta = \dfrac{mv^2}{r} cos \theta + \mu ((\dfrac{mv^2}{r}) sin \theta + mg cos \theta)[/tex]
[tex]\mu = \dfrac{mg sin \theta - \dfrac{mv^2}{r} cos \theta }{((\dfrac{mv^2}{r}) sin \theta + mg cos \theta) }[/tex]
[tex]\mu = \dfrac{g sin \theta - \dfrac{ v^2}{r} cos \theta }{((\dfrac{v^2}{r}) sin \theta + g cos \theta) }[/tex]
[tex]\mu = \dfrac{(9.8 \ m/s^2 ) sin (15^0) - \dfrac{ \dfrac{(25 \times 10^3}{3600} \ m/s)^2 }{100 \ m } cos (15^0) }{((\dfrac{(\dfrac{25 \times 10^3}{3600} )^2}{100}) sin 15^0 + (9.8 \ m/s^2) cos 15^0 ) }[/tex]
[tex]\mathbf{\mu = 0.216}[/tex]
Which two of the following involve the same energy transfer. Assume that the same substance and the same mass is involved in all four processes.
a. melting
b. evaporation
c. sublimation
d. condensation
3.
A person drives north 6 blocks, then drives west 6 blocks.
The displacement is a straight line from the starting point to the finish in a
direction
O A northwesterly
O B southwesterly
O c northeasterly
OD southeasterly
1. Amy uses 30N of force to push a lawn mower 10 meters. How much work does she do?
If 86 W is produced in 18 seconds, how much work is done?
Answer:86 parts = x + (x * 1.15)
86 = 2.15x
x = 40 parts and 1.15x = 46 parts
Explanation:
3. Explain why it is, regardless of the location, at a certain distance between the two points, you will perceive the two points as a single point rather than as two distinct points.
Answer:
Hello your question is missing some parts attached below is the missing part of your question
answer: many primary sensory Neurons will converge and become a single Neuron and the single Neuron will send a single harmonized signal to the Brain.
Explanation:
The reason regardless of the location that will make you perceive the two points as a single point rather than as two distinct points is that many primary sensory Neurons will converge and become a single Neuron and the single Neuron will send a single harmonized signal to the Brain.
A 56-kg woman contestant on a reality television show is at rest at the south end of a horizontal 149-kg raft that is floating in crocodile-infested waters. She and the raft are initially at rest. She needs to jump from the raft to a platform that is several meters off the north end of the raft. She takes a running start. When she reaches the north end of the raft she is running at 4.2 m/s relative to the raft. At that instant, what is her velocity relative to the water
Answer:
3.04 m/s
Explanation:
As the woman moves north, the raft moves south.
We then make the following assumptions for easier calculations
Let the motion of the woman = x
Let the motion of the raft = 4.2 - x
Using law of momentum, we see that
m*v = m1*v1, where
m = 56 kg
v = x
m1 = 149 kg
v1 = (4.2 -x)
Substituting the values into the equation, we have
56 * x = 149 (4.2 - x), opening the bracket
56x = 623 - 149x collecting like terms
205x = 623 Divide by 205
x = 623/205
x = 3.04 m/s
This then means that our answer is 3.04 m/s
What is the wavelength of a wave that has a speed of 350 meters second and a frequency of 140 hert??
Wavelength is the distance between identical points (adjacent crests) in the adjacent cycles of a waveform signal propagated in space or along a wire. In wireless systems, this length is usually specified in meters (m), centimeters (cm) or millimeters (mm).
Hope this helped
100 POINTS. PLEASE EXPLAIN
Answer:
Explanation:
Note the charge balls on the top and bottom row are identical. So those charges cancel each other out. The only charges in the net electric field are the two in the middle row.
Electric field strength = k*Q/r^2
= (8.99 *10^9) * (3-(-3)) * 5*10^(-6) / (2*0.5)^2
= 269700 N/C
Answer:
Explanation:
(b) cuz the 1st n 3nd row cancel out, net electric field will go from +3Q to -3Q. the direction is right.
A toy car, mass of 0.025 kg, is traveling on a horizontal track with a velocity of 5 m/s. If
the track then starts to climb upwards, how high up the track can the car reach?
Answer:
1.25 m
Explanation:
This is the vertical height not the distance along the slope.
[tex]K=U\\\frac{1}{2}mv^{2} = mgh\\h = \frac{v^{2}}{2g}=\frac{25}{20}=1.25 m[/tex]
The height the car can reach if the the track starts to climb upwards is 1.2742 meters up.
What is kinetic and potential energy?Kinetic energy is energy possessed by a body by virtue of its movement. Potential energy is the energy possessed by a body by virtue of its position or its relation with its surrounding systems.
P.E. = mass × g × height
K.E. = 0.5 × mass × (velocity)²
Given that the toy car has a mass of 0.025 kg and is traveling on a horizontal track with a velocity of 5 m/s. Now, the car starts to climb up vertically, therefore, the kinetic energy will be converted to potential energy.
Kinetic Energy = Potential Energy
0.5 × mass × (velocity)² = mass × g × height
Cancel mass from both the sides,
0.5 × (velocity)² = g × height
0.5 × (5 m/s)² = 9.81 m/sec² × height
height = 1.2742 meters
Hence, the car will travel 1.2742 meters up.
Learn more about Kinetic and Potential Energy here:
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A 2.0 kg block of ice with a speed of 8.0 m/s makes an elastic collision with another block of ice that is at rest. The first block of ice proceeds in the same direction as it did initially, but with a speed of 2.0 m/s. What is the mass of the second block? (Hint: Use the conservation of kinetic energy to solve for the second unknown variable.)
Answer:
6kg
Explanation:
According to conservation of kinetic energy
m1u1+m2u2 = (m1+m2)v
m1 and m2 are the masses of the bodies
u1 and u2 are the initial velocities
v is the final velocity
Given
m1 =2kg
u1 = 8.0m/s
m2 = ?
u2 = 0m/s (second ice at rest)
v = 2.0m/s
Substitute into the formula
2(8)+m2(0) = (2+m2)(2)
16+0 = 4+2m2
16-4= 2m2
12 = 2m2
m2 =12/2
m2 = 6kg
Hence the mass of the second block is 6kg
help it’s actually physical science but plz help
A 10 kg box initially at rest moves along a frictionless horizontal surface. A horizontal force to the right is applied to the box.A student calculates the impulse applied by force during the 2 seconds is 4 N.s. and that the impulse applied during the following 3 seconds is 6 Nâs.
Required:
a. What, if anything, is wrong with these calculations? If something is wrong, identify it and explain how to correct it. If these calculations are correct, explain why?
b. What is the difference between a perfectly elastic and an inelastic collision?
Answer:
The answer is below
Explanation:
a) Impulse is the total effect of force which has been acting on a body over a period of time. Impulse is the product of the force and the period of time applied. It is given by:
Impulse = force × time
Given that during 2 seconds, the impulse is 4 Ns, we can calculate the force applied.
Impulse = force × change in time
4 = force * 2
force = 4 / 2 = 2 N.
Hence the impulse applied during the following 3 seconds is:
Impulse = force × change in time = 2 * (2 + 3) = 2 * 5 = 10 Ns
The impulse applied during the following 3 seconds is 10 Ns not 6 Ns
b) In perfectly elastic collision, there is no loss in kinetic energy while in an inelastic collision there is loss in kinetic energy due to energy conversion or transfer.
In perfectly elastic collision the object does not stick together while in an inelastic collision the object stick together.
fired, the ball moves 15.9 cm through the horizontal barrel of the cannon, and the barrel exerts a constant friction force of 0.032 8 N on the ball. (a) With what speed does the projectile leave the barrel of the cannon
Answer:
Explanation:
Where is the remaining part of the question? This is a very easy one
A jumbo egg (80 grams) is dropped from a height of 15 meters onto a 1 inch of foam. Using kinematics, determine the velocity of the egg the instant before impact.
Answer:
the velocity of the egg the instant before impact is 17.15 m/s.
Explanation:
Given;
mass of the egg, m = 80 g = 0.08 kg
height through which the egg was dropped, h = 15 m
The velocity of the egg before impact will be maximum, and the final velocity is given by the following kinematic equation;
v² = u² + 2gh
where;
u is the initial velocity of the egg = 0
v is the final velocity of the egg before impact
v² = 0 + 2 x 9.8 x 15
v² = 294
v = √294
v = 17.15 m/s
Therefore, the velocity of the egg the instant before impact is 17.15 m/s.
Chemical energy is the stored form of chemical bonds containing combinations of which elements? Select THREE (3) elements. *
Carbon
Nitrogen
Helium
Hydrogen
Oxygen
Gold
Suppose the posted designated speed for a highway ramp is to be 30 mph and the radius of the curve is 700 ft. At what angle must the curve be banked? No Friction
Answer:
4.92°
Explanation:
The banking angle θ = tan⁻¹(v²/rg) where v = designated speed of ramp = 30 mph = 30 × 1609 m/3600 s = 13.41 m/s, r = radius of curve = 700 ft = 700 × 0.3048 m = 213.36 m and g = acceleration due to gravity = 9.8 m/s²
Substituting the variables into the equation, we have
θ = tan⁻¹(v²/rg)
= tan⁻¹((13.41 m/s)²/[213.36 m × 9.8 m/s²])
= tan⁻¹((179.8281 m²/s)²/[2090.928 m²/s²])
= tan⁻¹(0.086)
= 4.92°
A 9.0-kg box of oranges slides from rest down a frictionless incline from a height of 5.0 m. A constant frictional force, introduced at point A, brings the block to rest at point B, 19 m to the right of point A. What is the speed of the box just before it reaches point A
I'm going to assume that, judging by the fact that the coefficient of friction and angle of the incline seem to be intentionally left out, the point A refers to a point at the bottom of the incline, and the point B is located 19 m away from A on a horizontal surface. If this is not the case, please be sure to correct me!
Let v denote the speed of the box at point A, x the distance the box slides (without friction) down the incline, and θ the angle of the incline.
Recall that
v ² - v₀² = 2 a ∆x
where
v = final speed
v₀ = initial speed
a = acceleration
∆x = displacement
While on the incline, the box starts at rest (v₀ = 0) and slides a distance x from the starting point to point A with acceleration a to attain some speed v.
Use the free body diagram to determine the acceleration. By Newton's second law, the net force on the object acting parallel to the incline
∑ F = m g sin(θ) = m a → a = g sin(θ)
where m = 9.0 kg and g = 9.8 m/s².
Write the distance x in terms of θ with some trigonometry:
sin(θ) = (5.0 m) / x → x = (5.0 m) / sin(θ)
Now plug a and x into the formula above to solve for v :
v ² = 2 g sin(θ) ((5.0 m) / sin(θ))
v ² = (10.0 m) g
v ≈ 9.9 m/s
A Shaolin monk of mass 60 kg is able to do a ‘finger stand’: he supports his whole weight on his two index fingers, giving him a total contact area of 4 cm 2 with the ground. Calculate the pressure he exerts on the ground (include units), and write your answer to two significant figures.
Answer:
1500000 Pa
Explanation:
The formula for pressure is force per unit area.
P=F/A where F is force and A is area
Given that ;
F= mass * acceleration due to gravity
F= 60 * 9.81 = 588.6 = 589 N
A= area = 4cm² = 0.0004 m²
P= F/A = 589 / 0.0004
P= 1471500
P=1500000 Pa
Determine the gravitational field of Earth at a height 2.88 x 10^8 m above its surface (the height of the moon above Earth). Earth's mass is 6.0 x 10^24 kg and its radius is 6.4 x 10^6 m.
Answer:
12
Explanation:
Which statements correctly describe the formula or name of a compound? Select all that apply.
OA. The formula of nitrogen trifluoride is NF 3
B. The formula of ammonia is NH3.
C. The name of AlF, is trialuminum fluoride.
D. The formula of calcium chloride is CaCl2
E. The name of Li, Se is lithium selenate.
OF. The formula of dinitrogen monoxide is NO
2
Results
G. The formula of sulfur trioxide is 30.
Cho
Аа
H. The formula of magnesium hydroxide is Mg(OH)2
G.
Answer:
A, B, D, and H
Explanation:
Statements A, B, D and H are all correct except the following:
Statement C is incorrect. The name of [tex] AlF_3 [/tex] is aluminium fluoride NOT "trialuminium fluoride".
Statement E is incorrect. The name of [tex] Li_2Se [/tex] is lithium selenide NOT "lithium selenate".
Statement F is incorrect. Dinitrigen monoxide, also known as nitrous oxide has a formula of [tex] N_2O [/tex] NOT [tex] NO_2 [/tex].
Statement G is incorrect. Sulfur trioxide formula is [tex] SO_3 [/tex].
A Shaolin monk of mass 60 kg is able to do a ‘finger stand’: he supports his whole weight on his two index fingers, giving him a total contact area of 4 cm 2 with the ground. Calculate the pressure he exerts on the ground (include units), and write your answer to two significant figures.
Answer:
P = 1471500 [Pa]
Explanation:
We must remember that pressure is defined as the relationship between Force over the area.
[tex]P=F/A[/tex]
where:
P = pressure [Pa] (units of pascals)
F = force [N] (units of Newtons)
A = area of contact = 4 [cm²]
But first we must convert from cm² to m²
[tex]A = 4[cm^{2}]*\frac{1^{2} m^{2} }{100^{2} cm^{2} }[/tex]
A = 0.0004 [m²]
Also, the weight should be calculated as follows:
[tex]w = m*g[/tex]
where:
m = mass = 60 [kg]
g = gravity acceleration = 9.81 [m/s²]
Now replacing:
[tex]w = 60*9.81\\w = 588.6[N][/tex]
And the pressure:
[tex]P=588.6/0.0004\\P=1471500 [Pa][/tex]
Because 1 [Pa] = 1 [N/m²]
A physics grad student has a machine that measures how
many electrons are whizzing through a ring. If she measures 2
Coulombs of charge flowing through the ring every second,
what is the current passing through the ring?
1 = _A
Answer:
2A
Explanation:
Given parameter:
Quantity of charge = 2C
Time taken = 1s
Unknown:
The current passing through the ring = ?
Solution:
Current can also be defined as the quantity of charge that passes through a conductor per unit of time:
I = [tex]\frac{q}{t}[/tex]
So;
I = [tex]\frac{2}{1}[/tex] = 2A
Uri looks through a telescope for two stars. He knows that both stars have the same absolute brightness and that the second star is twice as far from Earth as the first star. How bright will the second star appear compared to the first star? SC.8.E.5.5
A. It will appear brighter than the first star.
B. It will appear dimmer than the first star.
C. It will appear as bright as the first star.
D. It will appear redder then the first star.
Answer:
b
Explanation: