Grade 11Mechanics

Find the torque of a force F(vector) =3i+j+5k at a point r(vector)=7i+3j+k
a) 14i-38j+16k
b) 4i+4j+6k
c) -21i+4j+4k
d) -14i+34j-16k

Ishika Mohanty

8 Years agoGrade 11

2 Answers

Arun

8 Years ago

Dear Ishika

Torque = r(vector) x F(vector)

Torque = (7i +3j +k) x (3i + j +5k)

Torque = 7k -35 j -9k +15 i + 3j -i

Torque = 14 i -32 j -2k

Options are wrong according to the data in the question.

Regards

Arun (askIITians forum expert)

Shashwat singh

7 Years ago

D is the correct option.

If we take i cap and k cap as negative and j cap as positive.

Then answer will be b

Three identical balls are placed on a frictionless horizontal surface touching each other. They stick to each other because of adhesive. Another ball of same radius and mass m is placed over the void created by the three balls. Find the forces applied by the balls kept on the floor to each other if the system remains in equilibrium.

mechanics

1 Answer Available

Last Activity: 10 Months ago

A car loaded with water having total mass 1000 kg moves on a straight horizontal Road starting from rest under the action of a force of 100 Newton. The water spills throw a small hole in the bottom at a rate of 0.1 KG per second the velocity of cart after 300 seconds is nearly.

11
21
31
41

mechanics

1 Answer Available

Last Activity: 10 Months ago

A metal strip clamped at one end vibrates with a frequency of 20 Hz and amplitude of 5 mm
at the free end, where a small mass of 2 g is positioned. determine
(i) The velocity of the end when passing through the zero position
(ii) The acceleration at maximum displacement
(iii) The maximum kinetic energy of the mass

mechanics

2 Answers Available

Last Activity: 3 Years ago

An object of mass m = 0.25 kg oscillates in a fluid at the end of a vertical spring of spring
constant kH = 85 N/m, see Fig.1. The effect of the fluid resistance is governed by the
damping constant b = 0.07kg/s.
(i) Find the period of the damped oscillation.
(ii) By what percentage does the amplitude of the oscillation decrease in each cycle?

mechanics

1 Answer Available

Last Activity: 3 Years ago

If a=x² find the displacement at t =3sec if body velocity at t= 0 sec is 0

mechanics

1 Answer Available

Last Activity: 3 Years ago

View all Questions

Find the torque of a force F(vector) =3i+j+5k at a point r(vector)=7i+3j+ka) 14i-38j+16kb) 4i+4j+6k c) -21i+4j+4kd) -14i+34j-16k

Ishika Mohanty

2 Answers

Arun

Shashwat singh

Other Related Questions on mechanics

A car loaded with water having total mass 1000 kg moves on a straight horizontal Road starting from rest under the action of a force of 100 Newton. The water spills throw a small hole in the bottom at a rate of 0.1 KG per second the velocity of cart after 300 seconds is nearly.11213141

If a=x² find the displacement at t =3sec if body velocity at t= 0 sec is 0

Find the torque of a force F(vector) =3i+j+5k at a point r(vector)=7i+3j+k
a) 14i-38j+16k
b) 4i+4j+6k
c) -21i+4j+4k
d) -14i+34j-16k

A car loaded with water having total mass 1000 kg moves on a straight horizontal Road starting from rest under the action of a force of 100 Newton. The water spills throw a small hole in the bottom at a rate of 0.1 KG per second the velocity of cart after 300 seconds is nearly.

11
21
31
41