All categories

3 years ago

In which activity is no work done?

Physics

2 answers:

Doss [256]3 years ago

5 0

Answer: The correct option is B.

Explanation:

Work is done when the force is applied to move an object to certain distance.

In the case of lifting a book, the work is done as the force is applied to lift the book. There will be displacement.

In the case of holding a brick, no work is done as the force is applied in this case but there is no displacement.

In the case of climbing stairs, work is done in climbing the stairs as the force is acting here. There will be displacement when the man will climb.

In the case of pushing a shopping cart, the work is done as the force is applied to a shopping cart. There will be displacement in forward direction.

Therefore, the correct answer is B.

sleet_krkn [62]3 years ago

3 0

The answer is B because you are not using force or energy as if you were if you were to lift or push something.

You might be interested in

Can anyone pls answer this plss plss I'm not sure which one it is

lyudmila [28]

Answer:

a) wet marble , dry marble, newspaper, and towel

5 0

2 years ago

Why are scientific theories modified, but seldom discarded?

scoundrel [369]

Because some scientific theories are true and some are false

5 0

2 years ago

Read 2 more answers

I will give brainliest if you sub and stay subbed to JD Outdoors & Gaming

jek_recluse [69]

First Stan txt (tomorrow by together) and stream freeze on YT Hybe labels !!!!!!!!!!!!!

5 0

2 years ago

I am struggling on this physics question. Brainly is my last hope. Could somebody please provide an answer to this question, wit

Aleks [24]

1) 29.4 N

The force of gravity between two objects is given by:

$F=G\frac{Mm}{r^2}$

where

G is the gravitational constant

M and m are the masses of the two objects

r is the separation between the centres of mass of the two objects

In this problem, we have

$M=5.97\cdot 10^{24} kg$ (mass of the Earth)

$m=3.0 kg$ (mass of the box)

$r=R=6.37\cdot 10^6 m$ (Earth's radius, which is also the distance between the centres of mass of the two objects, since the box is located at Earth's surface)

Substituting into the equation, we find F:

$F=\frac{(6.67\cdot 10^{-11})(5.97\cdot 10^{24})(3.0)}{(6.37\cdot 10^6)^2}=29.4 N$

2) $g=9.8 m/s^2$

Let's now calculate the ratio F/m. We have:

F = 29.4 N

m = 3.0 kg

Subsituting, we find

$\frac{F}{m}=\frac{29.4}{3.0}=9.8 N/kg = 9.8 m/s^2$

This is called acceleration of gravity, and it is the acceleration at which every object falls near the Earth's surface. It is indicated with the symbol $g$ .