1.A vault is opened by applying a force of 300 N perpendicular to the plane of the door, 0.80 m from the hinges. Find the torque due to this force about an axis through the hinges.a. 120 N⋅mb. 240 N⋅mc. 300 N⋅m d. 360 N⋅m2.A meter stick is supported by a knife-edge at the 50-cm mark. Doug hangs masses of 0.40 and 0.60 kg from the 20-cm and 80-cm marks, respectively. Where should Doug hang a third mass of 0.30 kg to keep the stick balanced?a. 20cmb. 70cm c. 30cm d. 25cm3.A copper wire of length 2.0 m, cross sectional area 7.1 × 10−6 m2 and Young's modulus 11 × 1010 N/m2 has a 200-kg load hung on it. What is its increase in length? (g = 9.8 m/s2)a. 0.50 mmb. 1.0 mmc. 2.5 mm d. 5.0 mm

Question
Asked Dec 12, 2019
44 views

1.A vault is opened by applying a force of 300 N perpendicular to the plane of the door, 0.80 m from the hinges. Find the torque due to this force about an axis through the hinges.
a. 120 N⋅m
b. 240 N⋅m
c. 300 N⋅m d. 360 N⋅m
2.A meter stick is supported by a knife-edge at the 50-cm mark. Doug hangs masses of 0.40 and 0.60 kg from the 20-cm and 80-cm marks, respectively. Where should Doug hang a third mass of 0.30 kg to keep the stick balanced?
a. 20cm
b. 70cm c. 30cm d. 25cm
3.A copper wire of length 2.0 m, cross sectional area 7.1 × 10−6 m2 and Young's modulus 11 × 1010 N/m2 has a 200-kg load hung on it. What is its increase in length? (g = 9.8 m/s2)
a. 0.50 mm
b. 1.0 mm
c. 2.5 mm d. 5.0 mm

check_circle

Expert Answer

Step 1

1.Write the expression for torque.

help_outline

Image Transcriptionclose

[risthe torque F is the force d is the dispalcement T=Fxd = 300 Nx0,80m =240 N-m Hence correct answer is option (b).

fullscreen
Step 2
  1. The third mass is 0.30kg must be on the left side. The torque about the pivot is equal to zero. Let x be the distance from left end.
help_outline

Image Transcriptionclose

0.30 kg (50cm - x)+0.40(50cm -20cm)0.60(80cm- 50cm) =0 x= 30 cm

fullscreen
Step 3

Thus option (c) is the correct answer. Thus Dong shou...

Want to see the full answer?

See Solution

Check out a sample Q&A here.

Want to see this answer and more?

Solutions are written by subject experts who are available 24/7. Questions are typically answered within 1 hour.*

See Solution
*Response times may vary by subject and question.
Tagged in

Science

Physics

Related Physics Q&A

Find answers to questions asked by student like you
Show more Q&A
add
question_answer

Q: A pitcher throws a 0.25 kg ball of clay at a stationary 3.0 kg block of wood. The Clay sticks to the...

A: Let v1 be the initial speed of the ball, and v be the final speed of the combined mass, m be the mas...

question_answer

Q: 40. A pendulum, comprising a light string of length L and a S small sphere, swings in the vertical p...

A:  When a pendulum is displaced sideways from its resting, equilibrium position it is subjected to a r...

question_answer

Q: A lightning stroke last 0.05 s and involves a flow of 100 c. What is the current?

A: Given data:Flow of charge,  Q = 100 cTime, t = 0.05 s

question_answer

Q: A bat can detect small insects whose size is approximately equal to one wavelength of the sound the ...

A: The bat detects insects of size approximately equal to one wavelength of its sound. The frequency of...

question_answer

Q: how to answer part b

A: Write the expression for first law of thermodynamics.

question_answer

Q: A uniform ladder of mass 24 kg and length 6 m leans at an angle of 45" against a smooth vertical wal...

A: Click to see the answer

question_answer

Q: A mass on the end of a string of length L is in clockwise uniform circular motion in the horizontal ...

A: Given:Mass = mLength of string = LTangential velocity = v 

question_answer

Q: Transcranial magnetic stimulation (TMS) is a noninvasive technique used to stimulate regions of the ...

A: Given:Initial value of magnetic field = 0 TFinal value of magnetic field = 1.9 TTotal Time taken = 1...

question_answer

Q: A 1000 kg race car is traveling at 60 m/s around a curved section of track that has a radius of 300 ...

A: a)Centripetal acceleration is