An object has a mass of 20 g and a volume of 5 cm3. what is the object's density? 4 g/cm3 100 g/cm3 0.25 g/cm3

A student weighing 700 N climbs at constant speed to the top of an 8 m vertical rope in 10 s. The average power expended by the

nasty-shy [4]

Answer:

The average power the student expended to overcome gravity is 560W, Watts is a units of work it is Joules /time or kg* $m^{2}$ / $s^{3}$

Explanation:

Weight = 700N

$F= m*g*h \\m*g= 700N\\F= 700N*h\\F=700N*8m\\F= 5600 N*m \\F=5600 J$

The power is the work in (Joules) or (N*m) in a determinate time (s) to get Watts (W) units for work

$Work= \frac{5600 J}{10s} = \frac{5600 \frac{kg*m^{2} }{s^{2} } }{10 s} \\Work= 560\frac{kg*m^{2} }{s^{3} } \\Work =560 W$

3 0

3 years ago

What is the gravitational acceleration close to the surface of a planet with a mass of 9ME and radius of 3RE, where ME and RE ar

Papessa [141]

Answer:

9.78 m/s²

Explanation:

To solve this, we use the gravitational formula

g = GM/r², where

g = acceleration due to gravity

G = gravitational constant

M = mass of the planet

r = radius of the planet

From the question, we got that the mass of the planet is

M = 9ME, where ME = 5.95*10^24

M = 9 * 5.95*10^24

M = 5.355*10^25 kg

Also, the Radius of the planet, R = 3RE, where RE = 6.37*10^6

R = 3 * 6.37*10^6

R = 1.911*10^7 m

On applying the values of both R and M to the equation, we get

g = GM/r²

g = (6.67*10^-11 * 5.355*10^25) / (1.911*10^7)²

g = 3.57*10^15/3.65*10^14

g = 9.78 m/s²

Therefore, the acceleration due to gravity on the planet is 9.78 m/s²

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5 0

3 years ago

Please help really easy worth 20

vovangra [49]

Answer:

Stationary

20N

Explanation:

From the graph, we see that the body traveling is on a fixed position. Therefore, it is a stationary body.

The graph given is a position - time curve.

This curve depict a body changing position with given time.

Since the line of the curve is on a single position, the body is not changing position with the passage of time therefore, it is a stationary object.

B. 20N

From Newton's third law of motion we understand that "action and reaction force are equal but oppositely directed".

Since the person is exerting a force of 20N on the balance.

So, the reaction force by the balance is 20N upward.

4 0

3 years ago

The owners want the speed at the bottom of the first hill doubled. How much higher must the first hill be built?

Sonja [21]

Neglecting friction and air resistance, the first hill must be built 4 times higher than it is now.

3 0

3 years ago

The object will feel minimum force of gravity at the

Alika [10]

Answer:

space , small amount of gravity is found in the space ,infact we can say that there is no gravity in the space

4 0

3 years ago

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