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
ira [324]
3 years ago
15

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
A baseball rolls off of a .7 m high desk and strikes the floor .25 m always how fast was the ball rolling
labwork [276]

Answer:

the ball's velocity was approximately 0.66 m/s

Explanation:

Recall that we can study the motion of the baseball rolling off the table in vertical component and horizontal component separately.

Since the velocity at which the ball was rolling is entirely in the horizontal direction, it doesn't affect the vertical motion that can therefore be studied as a free fall, where only the constant acceleration of gravity is affecting the vertical movement.

Then, considering that the ball, as it falls covers a vertical distance of 0.7 meters to the ground, we can set the equation of motion for this, and estimate the time the ball was in the air:

0.7 = (1/2) g t^2

solve for t:

t^2 = 1.4 / g

t = 0.3779  sec

which we can round to about 0.38 seconds

No we use this time in the horizontal motion, which is only determined by the ball's initial velocity (vi) as it takes off:

horizontal distance covered = vi * t

0.25 = vi * (0.38)

solve for vi:

vi = 0.25/0.38  m/s

vi = 0.65798  m/s

Then the ball's velocity was approximately 0.66 m/s

4 0
3 years ago
Formula for the distance (d) is given by d = rate*time. For example if you are traveling at 60 mph for 3 hours the distance trav
babunello [35]

Explanation:

Distance covered by the particle is given by:

Distance (d) = rate (v) × time (t)                

Speed of Mary, v₁ = 50 mph

Speed of Jim, v₂ = 60 mph

It is assumed that, Mary and Jim leave at the same time. After one hour, Jim is 10 miles ahead.

Distance travelled by Jim, d₁ = (60t + 10)

Distance travelled by Mary, d₂ = 50t

The distance between Mary and Jim is greater than or equal to 100 miles.

60t+10-50t\ge100

10t\ge90

t\ge9\ h

So, Jim takes is 9 hours more than Mary to cover same distance. Hence, this is the required solution.

7 0
3 years ago
A jet plane flying 600 m/s experiences an acceleration of 4g when pulling out of the dive. What is the radius of curvature of th
Gnoma [55]

Answer:

91.84 m/s²

Explanation:

velocity, v = 600 m/s

acceleration, a = 4 g = 4 x 9.8 = 39.2 m/s^2

Let the radius of the loop is r.

he experiences a centripetal force.

centripetal acceleration,

a = v² / r

39.2 x r = 600 x 600

r = 3600 / 39.2

r = 91.84 m/s²

Thus, the radius of the loop is 91.84 m/s².

8 0
3 years ago
What is the force on an object that accelerates at 2 m/s/s and has a mass of 120 kg
11111nata11111 [884]

Answer:

240 Newtons

Explanatiohn:

f = m × a

f = 120 × 2

f = 240 Newtons

<h3>The force is 240 Newtons</h3>
6 0
3 years ago
When touched by a plastic straw, the metal sphere will do what?
bearhunter [10]
I believe that if you touch a metal sphere with a plastic straw, the straw would not have enough strength to push it. So in that case, the metal sphere will not move and will stay in one place.

Please rate a 5 star
5 0
3 years ago
Other questions:
  • ASAP When salt is dissolved in water, the result is a A. gas B. compound C. homogeneous mixture D. heterogeneous mixture
    8·2 answers
  • n April 1974, Steve Prefontaine completed a 10 km race in a time of 27 min , 43.6 s . Suppose "Pre" was at the 7.57 km mark at a
    6·1 answer
  • How are the terms atom and element related
    15·2 answers
  • You are walking around your town. First you walk north from your startingposition and walk for 2 hours at 1 km/h. Then, you walk
    15·1 answer
  • A Chevy Camaro drives straight off the top level off a parking garage at 9 m/s. If the car landed 81 meters away from the base o
    11·1 answer
  • The length of a cylindrical axon is 8 cm and its radius of 8μm,and the thickness of the membrane is 0.01μm,dielectric constant (
    11·1 answer
  • PLS HELP BEING TIMED!!!
    9·2 answers
  • What would be the Elastic Potential Energy (EPE) stored in a spring with a constant k = 200 N/m that is pulled to stretch 0.45m?
    8·1 answer
  • A car is driving across a street. It's change in displacement is 50 m. If it started with a velocity of 5 m/s and ended with a v
    10·1 answer
  • Hello :) how to do 25 (b) ?
    15·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!