Relation between MA and VR

Q.

It is possible that acceleration of particle is non-zero and velocity is zero at same instant.

1. True
2. False

Q. An effort of 500 N is applied through 0.50 m on a machine, whose efficiency is 90%, such that resistance is overcome through 0.04 m. Calculate the mechanical advantage.

1. 10.25
2. 11.25
3. 12.25
4. 15.25

Q.

In which case work is done and why?

A boy swimming in a tank.

Q.

When the acceleration of particle is positive and is increasing, then its velocity must be positive.

1. True
2. False

Q.

Name the two kinds of motion that a given force can produce.

Q.

A force is applied on a body of mass $20kg$ moving with a velocity of $40m{s}^{-1}$.The body attains a velocity of $50m{s}^{-1}$in $2s$.Calculate the work done by the body.

Q.

A machine has a velocity ratio of 4. If It is used to raise a load of 400 N by 4 m using an effort of 20kgf, find the work done on the machine. Take g = 10 m/s${}^2$ .

1. 2000 J

2. 3200 J

3. 1600 J

4. 6400 J

Q. Determine the velocity ratio of a bicycle in which the ratio of teeth on the rear sprocket wheel to that on the front wheel is 1: 3

Q.

The unit of acceleration is

1. $\frac{m}{s}$

2. $\frac{m}{min}$

3. $\frac{km}{hr}$

4. $\frac{km}{mi{n}^2}$

Q.

How is mechanical advantage related to the velocity ratio for an ideal machine?

1. Mechanical advantage is equal to the velocity ratio.

2. Mechanical advantage is always greater than the velocity ratio.

3. Mechanical advantage is always less than the velocity ratio.

4. None of these.

Q. The relationship between the mechanical advantage (MA), the velocity ratio (VR) and the efficiency (n) is:

1. M.A = $n\times V.R$

2. V.R. = $n\times M.A$

3. n= $M.A\times V.R$

4. M.A = $n^2\times V.R$