Ask question

Ask question

All categories

3 years ago

8

Type the correct answer in the box. Round your answer to the nearest whole number. Calculate the man’s mass. (Use PE = m × g × h

, where g = 9.8 N/kg.) A man climbs a wall that has a height of 8.4 meters and gains a potential energy of 4,620 joules. His mass is about kilograms.

2 answers:

Blababa [14]3 years ago

6 0

Answer:

56 kg

Explanation:

The change in potential energy of the man is given by:

$\Delta U = mg \Delta h$

where

m is the man's mass

g is the gravitational acceleration

$\Delta h$ is the change in height of the man

In this problem, we have:

$\Delta U=4620 J$ is the gain in potential energy

g = 9.8 m/s^2 is the gravitational acceleration

$\Delta h=8.4 m$ is the change in height

Re-arranging the equation and substituting the numbers, we find the mass:

$m=\frac{\Delta U}{g\Delta h}=\frac{4620 J}{(9.8 m/s^2)(8.4 m)}=56 kg$

Vsevolod [243]3 years ago

3 0

Answer:

56 kg

Explanation:

You might be interested in

Did I do these questions correctly?

SOVA2 [1]

Yes, they seem right to me.

4 0

3 years ago

An electron, moving south, enters a uniform magnetic field. Because of this uniform magnetic field, the electron curves upward.

Flura [38]

Answer:

Towards the west

Explanation:

Magnetic force is the interaction between a moving charged particle and a magnetic field.

Magnetic force is given as

F = q (V × B)

Where F is the magnetic force

q is the charge

V is the velocity

B is the magnetic field

V×B means the cross product of the velocity and the magnetic field

NOTE:

i×i=j×j×k×k=0

i×j=k. j×i=-k

j×k=i. k×j=-i

k×i=j. i×k=-j

So, if the electron is moving southward, then, it implies that the velocity of it motion is southward, so the electron is in the positive z-direction

Also, the electron is curved upward due to the magnetic field, this implies that the force field is directed up in the positive y direction.

Then,

V = V•k

F = F•j

Then, apply the theorem

F •j = q ( V•k × B•x)

Let x be the unknown

From vector k×i =j.

This shows that x = i

Then, the magnetic field point in the direction of positive x axis, which is towards the west

You can as well use the Fleming right hand rule

The thumb represent force

The index finger represent velocity

The middle finger represent field

3 0

3 years ago

List the four outer planets from smallest to largest.<br> WILL MARK BRAINLIEST! ASAP

dusya [7]

Answer: Mercury, Mars, Venus, Earth, Neptune, Uranus, Saturn, and Jupiter.

Explanation:

That's all of the planets if you need them. Hope this helps!

8 0

2 years ago

Suppose we repeat the experiment from the video, but this time we use a rocket three times as massive as the one in the video, a

shusha [124]

Answer:

2/3

Explanation:

In the case shown above, the result 2/3 is directly related to the fact that the speed of the rocket is proportional to the ratio between the mass of the fluid and the mass of the rocket.

In the case shown in the question above, the momentum will happen due to the influence of the fluid that is in the rocket, which is proportional to the mass and speed of the same rocket. If we consider the constant speed, this will result in an increase in the momentum of the fluid. Based on this and considering that rocket and fluid has momentum in opposite directions we can make the following calculation:

Rocket speed = rocket momentum / rocket mass.

As we saw in the question above, the mass of the rocket is three times greater than that of the rocket in the video. For this reason, we can conclude that the calculation should be done with the rocket in its initial state and another calculation with its final state:

Initial state: Speed = rocket momentum / rocket mass.

Final state: Speed = 2 rocket momentum / 3 rocket mass. -------------> 2/3

8 0

3 years ago

In creating his definition of horsepower, James Watt, the inventor of the steam engine, calculated the power output of a horse o

Studentka2010 [4]

Answer:

Part a)

$F = 182.3 Lb$

Part b)

$P = 0.55 HP$

Explanation:

Diameter of the circle = 24 ft

Diameter = 731.52 cm = 7.3152 m

now the horse complete 144 trips in one hour

so time to complete one trip is given as

$t = \frac{3600}{144} s$

$t = 25 s$

now the speed of the horse is given as

$v = \frac{2\pi r}{t}$

$v = \frac{\pi(7.3152)}{25}$

$v = 0.92 m/s$

Part a)

Now we know that the power is defined as rate of work done

it is given as

$P = F v$

$746 = F(0.92)$

$F = 810.9 N$

$F = 182.3 Lb$

Part b)

Work done to climb up to 3 m height is given by

$W = mgh$

now we have

$Power = \frac{Work}{time}$

$P = \frac{mgh}{t}$

$P = \frac{(70kg)(9.81)(3)}{5.0s}$

$P = 412.02 Watt$

now we know that 1 HP = 746 Watt

so we have

$P = \frac{412}{746} = 0.55 HP$

8 0

2 years ago