Answer:
A. 450 N
B. 3240 J
C. 0.77 KW
Explanation:
From the question given above, the following data were obtained:
Height of one step = 20 cm
Number of steps = 36
Mass of runner = 45 kg
Time taken = 4.2 s
Next, we shall convert 20 cm to metre (m). This can be obtained as follow:
100 cm = 1 m
Therefore,
20 cm = 20 cm × 1 m /100 cm
20 cm = 0.2 m
Next, we shall determine the total height. This can be obtained as follow:
Height of one step = 0.2 m
Number of steps = 36
Total height =?
Total height = 36 × 0.2
Total height = 7.2 m
A. Determination of the runner's weight.
Mass of runner (m) = 45 kg
Acceleration due to gravity (g) = 10 m/s²
Weight (W) =?
W = m × g
W = 45 × 10
W = 450 N
B. Determination of the increase in the potential energy.
At the ground level, the potential energy (PE₁) is 0 J.
Next, we shall determine the potential energy at 7.2 m. This can be obtained as follow:
Mass of runner (m) = 45 kg
Acceleration due to gravity (g) = 10 m/s²
Total height (h) = 7.2 m
Potential energy at height 7.2 m (PE₂) = ?
PE₂ = mgh
PE₂ = 45 × 10 × 7.2
PE₂ = 3240 J
Final, we shall determine the increase in potential energy. This can be obtained as follow:
Potential energy at ground (PE₁) = 0 J
Potential energy at height 7.2 m (PE₂) = 3240 J
Increase in potential energy =?
Increase in potential energy = PE₂ – PE₁
Increase in potential energy = 3240 – 0
Increase in potential energy = 3240 J
C. Determination of the power.
Energy (E) = 3240 J
Time (t) = 4.2 s
Power (P) =?
P = E/t
P = 3240 / 4.2
P = 771.43 W
Finally, we shall convert 771.43 W to kilowatt (KW). This can be obtained as follow:
1000 W = 1 KW
Therefore,
771.43 W = 771.43 W × 1 KW / 1000 W
771.43 W = 0.77 KW
Therefore, her power is 0.77 KW
(iii) Gareth cycles 5 laps at this constant spoed. Each lap is 500m.
Calculate the distance he travels.
I
Distance
Answer:
2500 m
Explanation:
Given that,
Each lap is 500 m
Gareth takes 5 laps.
We need to find distance traveled by Gareth. The distance covered by him is given by :
d = 5×500
d = 2500 m
Hence, he will travel 2500 m.
1. What does the Work-Energy Theorem state?
Work is equal to the change in kinetic energy
Work is equal to the change in momentum
Work is equal to the change in impulse
Work is equal to the change in position
The Work-Energy Theorem states that Work is equal to the change in kinetic energy, which is the first option . This theorem is an essential principle in physics and mechanics, so first option is correct.
Work (W) is a measure of the energy transferred to or from an object by a force acting on it. It is defined as the product of the force applied to the object and the displacement of the object in the direction of the force. When a force does positive work on an object, it transfers energy to the object, increasing its kinetic energy. Conversely, when a force does negative work on an object (opposite to its direction of motion), it takes energy away from the object, decreasing its kinetic energy. So, first option is correct.
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what dose current equal?
If a spring extends by 3 cm when a 4 N weight is suspended from it, find the extension
when the weight is changed to
(a) 8 N
(b) 10 N
(c) 14
Take 100 PONTS!!!!!! PLEASE I NEED HELP FAST. Just look The picture.
Answer:
i THINK it’s false. You don’t have to give me points ;-;
Explanation:
Answer:
i think false and true is spelt wrong lol
Explanation:
___________is
objects total kinetic and potential energy.
Answer:
Bowling ball
Explanation:
What might Earth be like if it had never been hit by the theoretical protoplanet Orpheus?
Answer:
If Earth hadn't been hit by Orpheus, it would be covered by ocean, with perhaps a few mountaintops emerging through the water. There would be no humans, but there could be other forms of life. Earth would rotate rapidly, as the moon would not be present to produce the tidal friction that slows Earth's rotation today
Object 1 has a momentum of 10 kg m/s and Object 2 has a momentum of 25 kg m/s. Will it be easier to change the direction of movement of Object 1 or of Object 2?
Answer:
I think its object 1
Explanation:
Because the object that has more weight has a greater momentum and the lightest object that has a less momentum will be easier to change because its lighter.
What x rays travel at the speed of
6)
A 50 kg bike and rider accelerate from 4 to 8 m Determine how much kinetic energy must be added to make this occur?
S
S
A)
200
B)
400)
800)
D)
1200
Answer:
A.) 200 in my opinion so I hope this helps
Answer: 1200 j
Explanation:
I just took it
In 1666 at the age of 23, what scientist
developed the theories of gravitation inspired
by an apple falling from a tree?
A. Galileo Galilei
B. Issac Newton
C. Albert Einstein
D. Nicolaus Copernicus
Answer:
B - Isaac NewtonExplanation:
He first thought of his system of gravitation which he hit upon by observing an apple fall from a tree,
The incident occurring in the late summer of 1666.
During a normal reaction to a stressful event, muscles are moved to their maximum capacity, and sensitivity is
Answer:
The paper focuses on the biology of stress and resilience and their biomarkers in humans from the system science perspective. A stressor pushes the physiological system away from its baseline state toward a lower utility state. The physiological system may return toward the original state in one attractor basin but may be shifted to a state in another, lower utility attractor basin. While some physiological changes induced by stressors may benefit health, there is often a chronic wear and tear cost due to implementing changes to enable the return of the system to its baseline state and maintain itself in the high utility baseline attractor basin following repeated perturbations. This cost, also called allostatic load, is the utility reduction associated with both a change in state and with alterations in the attractor basin that affect system responses following future perturbations. This added cost can increase the time course of the return to baseline or the likelihood of moving into a different attractor basin following a perturbation. Opposite to this is the system's resilience which influences its ability to return to the high utility attractor basin following a perturbation by increasing the likelihood and/or speed of returning to the baseline state following a stressor. This review paper is a qualitative systematic review; it covers areas most relevant for moving the stress and resilience field forward from a more quantitative and neuroscientific perspective.
Explanation:
During a normal reaction to a stressful event, muscles are moved to their maximum capacity, and sensitivity is increased.
What is Sensitivity?This is defined as the ability of an organism to respond to stimuli such as touch, sensation etc.
During exercise, sensitivity to substances such as insulin when glucose transport wears off helps to balance energy supply.
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Help please, i am lost.
Answer:
nas wr hdrtuendnetyje because
Explanation:
Which task would be impossible without radio waves ?
Answer:
checking your e-mail on your computer using a coffee's shop WiFi. No need radio waves for this.
Explanation:
Because you are only checking it, nothing else.
A tank is is half full of oil that has a density of 900 kg/m3. Find the work W required to pump the oil out of the spout. (Use 9.8 m/s2 for g. Assume r = 15 m and h = 5 m.) W = 1.59 J
Answer:
3.9 × 10^7 J
Explanation:
Given that a tank is is half full of oil that has a density of 900 kg/m3. Find the work W required to pump the oil out of the spout. (Use 9.8 m/s2 for g. Assume r = 15 m and h = 5 m.) W = 1.59 J
Solution
Since the tank is half full, the height = 2.5m
Pressure = density × gravity × height
Pressure = 900 × 9.8 × 2.5
Pressure = 22050 Pascal
The cross sectional area of the pump will be area of a circle.
A = πr^2
A = π × 15^2
A = 706.858 m^2
Using the formula
Density = mass/volume
Mass = density × volume
Mass = 900 × 706.86 × 2.5
Mass = 1590.435
Energy = mgh
Energy = 1590.435 × 9.8 × 2.5
Energy = 38965657.8 J
Since the work done = energy
Therefore, the work done = 3.9 × 10^7 J
A 7.80 g bullet has a speed of 620 m/s when it hits a target, causing the target to move 6.30 cm in the direction of the bullet's velocity before stopping. (a) Use work and energy considerations to find the average force (in N) that stops the bullet. (Enter the magnitude.) N (b) Assuming the force is constant, determine how much time elapses (in s) between the moment the bullet strikes the target and the moment it stops moving. s
Answer:
[tex]23796.19\ \text{N}[/tex]
[tex]0.0002032\ \text{s}[/tex]
Explanation:
F = Force
s = Displacement = 6.3 cm
m = Mass of bullet = 7.8 g
v = Velocity of bullet = 620 m/s
t = Time taken
Work done is given by
[tex]W=Fs[/tex]
Kinetic energy is given by
[tex]K=\dfrac{1}{2}mv^2[/tex]
Using work energy considerations we get
[tex]Fs=\dfrac{1}{2}mv^2\\\Rightarrow F=\dfrac{1}{2s}mv^2\\\Rightarrow F=\dfrac{1}{2\times 0.063}\times 7.8\times 10^{-3}\times 620^2\\\Rightarrow F=23796.19\ \text{N}[/tex]
The average force that stops the bullet is [tex]23796.19\ \text{N}[/tex].
Force is given by
[tex]F=m\dfrac{v-u}{t}\\\Rightarrow t=m\dfrac{v-u}{F}\\\Rightarrow t=7.8\times 10^{-3}\times \dfrac{620}{23796.19}\\\Rightarrow t=0.0002032\ \text{s}[/tex]
The time taken to stop the bullet is [tex]0.0002032\ \text{s}[/tex].
If an object is placed at distance of 16cm from a plane mirror, How far would it be from it's image?
Explanation:
A plane mirror always creates an image with the same distance to the mirror as the object, only in the other direction. So both of them have a distance of 10cm, one is 10cm to the left, one 10cm to the right, thus their mutual distance is 20cm
A gun is fired on a day when the speed of sound is 335 m/s and an echo is heard 0.75 seconds later. How far away is the object that created the echo?
Answer:
v= 335 m/s
2∆t= 0.75 s
∆x= v.∆t → ∆x= 335×½×0.75 = 125.625 m
HELP
HELP
SORRY TO BEG :/
HELP ASAP :) PLZ
Answer:
It's b because he discovered galaxies .
14. Which of the following is not an example of work being done?
A. pushing a basketball away from your body
B. holding a coffee mug
C. carrying boxes across a warehouse floor
Answer:
B. holding a coffee mug
Explanation:
Something must move a distance for work to be done.
a ball is spun around in circular motion such that it completes 50 rotations in 25 s.
1) What is the period of its rotation?
2) what is the frequency of its rotation?
Answer:
(A) The period of its rotation is 0.5 s (2) The frequency of its rotation is 2 Hz.
Explanation:
Given that,
a ball is spun around in circular motion such that it completes 50 rotations in 25 s.
(1). Let T be the period of its rotation. It can be calculated as follows :
[tex]T=\dfrac{25}{50}\\\\T=0.5\ s[/tex]
(2). Let f be the frequency of its rotation. It can be defined as the number of rotations per unit time. So,
[tex]f=\dfrac{50}{25}\\\\f=2\ Hz[/tex]
Hence, this is the required solution.
If a person walks 3 m north and 5 meters east, how would you find the displacement for that person? what would the displacement be?
Answer:
AC)=(AB)2+(BC)2−−−−−−−−−−−−√=42+32−−−−−−√
⇒displacement=16+9−−−−−√=25−−√=5m
A friend pushes a sled across horizontal snow and when it gets up to speed the friend jumps on. After the friend jumps on, the sled gradually slows down. Which forces act on the combined sled plus friend after the friend jumps on
Answer:
v’ =( [tex]\frac{1}{1+ \frac{M}{m} }[/tex] ) v
we see that the greater the difference, the more the sled slows down.
friction force
Explanation:
When the man pushes the sled he does work and the sled acquires a speed and as long as it is supplied with an energy equal to the work of the chipping force with the snow, the speed is maintained.
When he jumps on the sled, a collision occurs and the initial moment
p₀ = mv
is increased by the increase in mass
m_f= (m + M_{man} ) v '
In this case there is no longer any external force applied and the only external force is friction, which causes the sled to stop, even when it is small, but the significant reduction in speed is due to the increase in masses.
p₀ = p_f
mv = (m + M_{man}) v '
v ’= [tex]\frac{m}{m+M}[/tex] v
v’ =( [tex]\frac{1}{1+ \frac{M}{m} }[/tex] ) v
Therefore, we see that the greater the difference, the more the sled slows down.
The only forces that act on the sled with the man are the friction that is responsible for the decrease in speed and weight with the normal
1. Describe how unequal heating and rotation of the Earth causes atmospheric and oceanic circulation patterns that determine the regional and global climate.
If a 15 N box is lifted a distance of 3 m, how much work is done?
0 J
45 J
5 J
5 N
Answer:
W=45J
Explanation:
W=Fd
W=15(3)=45
W=45J
HELP me please cause I don't understand it.
Answer:
Force = 0.49 N (Approx)
Explanation:
Given:
Mass = 50 grams = 0.05 Kg
Acceleration = 9.81 m/s²
Find:
Force
Computation:
Force = Mass x Acceleration
Force = 0.05 x 9.81
Force = 0.4905
Force = 0.49 N (Approx)
The rate at which work is done is known as which of the following?
A. Power,
B. Energy,
C. Momentum,
Answer:
A , power
Explanation:
Hope this is useful. Have a lovely rest of your day! God bless you.
if you ride a bike at 2 km/h and travel a total distance of 20km, how long willnit takr ( in second) you to teach your destination
Time = (20 km) x (1 hr/2 km) x (3,600 sec/hr)
Time = (20 x 1 x 3,600 km-hr-sec) / (2 km-hr)
Time = (20 x 1 x 3,600 / 2) (km-hr-sec / km-hr)
Time = 36,000 seconds
(That's 10 hours.)
What is the magnitude of the force that is exerted on a 20 kg mass to give it an acceleration of 10.0
m/s2?
Answer:Mass of the body = 20 kg.
Final Velocity = 5.8 m/s.
Initial velocity = 0
Time = 3 seconds.
Using the Formula,
Acceleration = (v - u)/ t
= (5.8 - 0)/ 3
= 1.6 m /s².
Now, Using the Formula,
Force = mass × acceleration
= 20 × 1.6
=
Explanation: I REALLY HOPE THIS HELPS I'M KINDA NEW AT THIS :] :]
The magnitude of requires force, that is exerted on a 20 kg mass to give it an acceleration of 10.0 m/s^2 is 200 Newton.
What is force?The definition of force in physics is: The push or pull on a mass-containing item changes its velocity.
An external force is an agent that has the power to alter the resting or moving condition of a body. It has a direction and a magnitude. The application of force is the location at which force is applied, and the direction in which the force is applied is known as the direction of the force.
Given parameters:
Mass of the object: m = 20 kg.
Acceleration of the object: a = 10.0 m/s^2.
Hence, according to Newton's 2nd law of motion:
the magnitude of requires force = mass ×acceleration
= 20 × 10 Newton
= 200 Newton.
Hence, the magnitude of requires force is 200 Newton.
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A 65.0 kg skier slides down a 37.20 slope with mu = 0.107.
What is the friction force?
Answer:
54.3N
Explanation:
The normal force is perpendicular to the slope, so:
Normal Force = cos(37.2)(9.8*65).......507.39N
F(friction)=mu*F(normal)
F(friction)=(0.107)(507.39)
F(friction)=54.3N
Answer:
magnitude of friction force- 54.3
friction force- -54.2
Explanation: