1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
dem82 [27]
3 years ago
14

9. A 50 kg physics i student trudges from the 1st floor to the 3rd floor, going up a total height of 13 m.

Physics
1 answer:
SVETLANKA909090 [29]3 years ago
3 0

Answer:

6370 J

Explanation:

By the law of energy conservation, the work done by the student would be the change in potential enegy from 1st floor to 3rd floor, or a change of 13 m

W = E_p = mgh

where m = 50kg is the mass of the student, g = 9.8 m/s2 is the gravitational constant and h = 13 m is the height difference

W = 50*9.8*13 = 6370 J

You might be interested in
You find it takes 200 N of horizontal force tomove an unloaded pickup truck along a level road at a speed of2.4 m/s. You then lo
IgorC [24]

ANSWER:

F(h)= 230 N is the horizontal force you will need to move the pickup along the same road at the same speed.

STEP-BY-STEP EXPLANATION:

F(h) is Horizontal Force = 200 N

V is Speed = 2.4 m/s

The total weight increase by 42%

coefficient of rolling friction decrease by 19%

Since the velocity is constant so acceleration is zero; a=0

Now the horizontal force required to move the pickup is equal to the frictional force.

F(h) = F(f)

F(h) = mg* u

m is mass

g is gravitational acceleration = 9.8 m/s^2

200 = mg*u

Since weight increases by 42% and friction coefficient decreases by 19%

New weight = 1+0.42 = 1.42 = (1.42*m*g)

New friction coefficient = μ = 1 - 0.19 = 0.81 = 0.81 u

F(h) = (0.81μ) (1.42 m g)

       = (0.81) (1.42) (μ m g)

       = (0.81) (1.42) (200)

       = 230 N

4 0
3 years ago
The amount of heat required to melt lead at it melting temperature is 23.0 kJ/kg. The amount of heat required to melt mercury at
svet-max [94.6K]

The addition of 24 kJ of energy will allow all of the mercury and lead to change from solid to liquid. The temperature of each substance will also increase.

4 0
3 years ago
Read 2 more answers
Imagine that the earth and the-moon have positive charges of the same magnitud. How big isäºthe charge necesary to produce an el
lions [1.4K]

Answer:

5.7 x 10^12 C

Explanation:

Let the charge on earth and moon is q.

mass of earth, Me = 5.972 x 10^24 kg

mass of moon, Mm = 7.35 x 10^22 kg

Let d be the distance between earth and moon.

the gravitational force between them is

F_{g}=G\frac{M_{e} \times M_{m}}{d^{2}}

The electrostatic force between them is

F_{e}=\frac{Kq^{2}}{d^{2}}

According to the question

1 % of Fg = Fe

0.01 \times 6.67\times10^{-11}\frac{5.97 \times 10^{24}\times7.35 \times 10^{22}}{d^{2}}=9 \times 10^{9}\frac{q^{2}}{d^{2}}

2.927 \times 10^{35}=9 \times10^{9}q^{2}

3.25 \times 10^{25}=q^{2}

q = 5.7 x 10^12 C

Thus, the charge on earth and the moon is 5.7 x 10^12 C.

6 0
3 years ago
Which word describes the maximum a point moves from its rest position when a wave passes?
Tom [10]

Answer:

Amplitude.

Explanation:

A wave can be defined as a disturbance in a medium that progressively transports energy from a source location to another location without the transportation of matter.

In Science, there are two (2) types of wave and these include;

I. Electromagnetic waves: it doesn't require a medium for its propagation and as such can travel through an empty space or vacuum. An example of an electromagnetic wave is light.

II. Mechanical waves: it requires a medium for its propagation and as such can't travel through an empty space or vacuum. An example of a mechanical wave is sound.

An amplitude can be defined as a waveform that's measured from the center line (its origin or equilibrium position) to the bottom of a trough or top of a crest.

Hence, an amplitude is a word that describes the maximum displacement a point moves from its rest position when a wave passes.

On a graph, the vertical axis (y-axis) is the amplitude of a waveform and this simply means that, it's measured vertically.

Mathematically, the amplitude of a wave is given by the formula;

x = Asin(ωt + ϕ)

Where;

x is displacement of the wave measured in meters.

A is the amplitude.

ω is the angular frequency measured in rad/s.

t is the time period measured in seconds.

ϕ is the phase angle.

6 0
3 years ago
A spherical balloon is inflating with helium at a rate of 72 ft2/min . How fast is the​ balloon's radius increasing at the insta
Yanka [14]

The volume of the balloon is given by:

V = 4πr³/3

V = volume, r = radius

Differentiate both sides with respect to time t:

dV/dt = 4πr²(dr/dt)

Isolate dr/dt:

dr/dt = (dV/dt)/(4πr²)

Given values:

dV/dt = 72ft³/min

r = 3ft

Plug in and solve for dr/dt:

dr/dt = 72/(4π(3)²)

dr/dt = 0.64ft/min

The radius is increasing at a rate of 0.64ft/min

The surface area of the balloon is given by:

A = 4πr²

A = surface area, r = radius

Differentiate both sides with respect to time t:

dA/dt = 8πr(dr/dt)

Given values:

r = 3ft

dr/dt = 0.64ft/min

Plug in and solve for dA/dt:

dA/dt = 8π(3)(0.64)

dA/dt = 48.25ft²/min

The surface area is changing at a rate of 48.25ft²/min

7 0
3 years ago
Other questions:
  • Why is there a universe at all
    10·1 answer
  • The parallax method of measuring star distances gives most accurate results when the gap between two observations of a star is a
    11·2 answers
  • The blackbody curve of a star moving toward Earth would have its peak shifted (a) to lower intensity; (b) toward higher energies
    7·1 answer
  • you want to compare brands of paper towels to see which holds the most liquid. the independent variable in your experiment would
    15·1 answer
  • What Science is/is not and How Physics and Chemistry are Connected
    7·1 answer
  • When the termination is a terminal block, care must be taken to ensure a good electrical connection without damaging the conduct
    14·1 answer
  • There are four coils of wire being used as electromagnets. They all have the same size and are made up of the same material but
    15·1 answer
  • The human nervous system can propagate nerve impulses at about 102 m>s. Estimate the time it takes for a nerve impulse to tra
    10·1 answer
  • Two spherical objects have masses of 100 kg and 200 kg. Their centers are
    7·1 answer
  • How long does it take for a bee traveling 11.34 m/s to fly 120 m?
    13·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!