Class 1 Lever When MA>1

Q.

What is the purpose of a jack in lifting a car by it ?

Q.

Name a machine for each of the following use :

(a) to multiply the force,

(b) to change the point of application of force,

(c) to change the direction of force,

(d) to obtain the gain in speed.

Q.

A man uses a crowbar of length 1.5m to raise a load of 75 kgf by putting a sharp edge below the bar at a distance of 1m from his hand. (a) Draw a diagram of the arrangement showing the fulcrum (F), load (L) and effort (E) with their directions. (b) State the kind of lever. (c) Calculate (i) load arm, (ii) effort arm, (iii) mechanical advantage, and (iv) the effort needed.

Q.

A force of 5 kgf is required to cut a metal sheet. A shears used for cutting the metal sheet has its blades 5 cm long, while its handles are 10 cm long . What effort is needed to cut the sheet ?

Q.

A nut can be opened by a lever of length $0.25m$ by applying a force of $80N$. What should be the length of the lever if a force of $32N$ is enough to open the nut?

Q. In the following levers, mark the load, effort, and fulcrum. Also, identify the class these levers belong to and comment on their $\text{MA}$ and $\text{VR}$.

$\left(a\right)$



$\left(b\right)$

Q. In a class $3$ lever, the distance between the effort and the load point is $25\text{cm}$, and the load arm is $0.75\text{m}$ long. Find the length of the effort arm and then calculate the mechanical advantage of the lever. $\left[5\text{marks}\right]$

Q.

A man uses a crowbar of length 1.5 m to raise a load of 75 kgf by putting a sharp edge below the bar at a distance 1 m from his hand. State the kind of lever and calculate the effort needed.

1. Class II lever, 35 kgf

2. Class I lever, 37.5 kgf

3. Class III lever, 37.5 kgf

4. Class I lever, 35 kgf

Q.

If the effort arm of a lever is longer than the load arm, then its mechanical advantage will be

1. one

2. more than one

3. less than one

4. zero

Q. A man uses a crowbar of length $2.5\text{m}$ to raise a load of $75\text{kgf}$ by putting a sharp edge below the bar at a distance $1\text{m}$ from his hand. State the kind of lever used and calculate the effort needed.

1. Class $\text{II}$ lever, $35\text{kgf}$
2. Class $\text{I}$ lever, $35\text{kgf}$
3. Class $\text{I}$ lever, $50\text{kgf}$
4. Class $\text{III}$ lever, $37.5\text{kgf}$

Q. Which of the following always has the mechanical advantage of less than 1?

[1 mark]

1. Class I lever
2. Class III lever
3. Class II lever
4. None of the above

Q.

A man uses a crowbar of length 1.5 m to raise a load of 75 kgf by putting a sharp edge below the bar at a distance 1 m from his hand. State the kind of lever and calculate the effort needed.

1. Class II lever, 35 kgf

2. Class I lever, 37.5 kgf

3. Class III lever, 37.5 kgf

4. Class I lever, 35 kgf

Q.

Which one of the following is an example of class I lever and M.A >1?

1. Seesaw

2. A physical balance

3. Scissors

4. Claw Hammer

Q.

Which one of the following is an example of class I lever and M.A >1?

1. Seesaw

2. Scissors

3. Claw Hammer

4. A physical balance

Q. The type of lever has the M.A. always greater than 1 is

1. Class I
2. Class II
3. Class III
4. All of the above.

Q.

Give one example each of a class I lever where mechanical advantage is (a) more than 1, and (b) less than 1.

Q. Identify the class I levers in the following.

1. Bottle opener
2. Seesaw
3. Hammer
4. Knife
5. Crowbar
6. Scissors
7. Water pump
8. Nutcracker

Q.

The mechanical advantage of a class II levers is always more than 1, because

1. the effort arm is always longer than the load arm.

2. the effort arm is always smaller than the load arm.

3. the effort arm is always equal to the load arm.

4. there is no load

Q.

A man uses a crowbar of length 1.5m to raise a load of 75 kgf by putting a sharp edge below the bar at a distance of 1m from his hand. (a) Draw a diagram of the arrangement showing the fulcrum (F), load (L) and effort (E) with their directions. (b) State the kind of lever. (c) Calculate (i) load arm, (ii) effort arm, (iii) mechanical advantage, and (iv) the effort needed.

Q. Which one of the following is an example of class $\text{I}$ lever and $\text{MA}>1$?

Q.

An uniform metre scale is balanced at 60 cm mark, When weight of 5 gf and 40 gf are suspended at 10 cm mark and 80 cm mark respectively. Calculate the weight of metre scale.

Q. The type of lever has the M.A. always greater than 1 is

1. Class I
2. Class II
3. Class III
4. All of the above.

Q.

The mechanical advantage of a class II levers is always more than 1, because

1. the effort arm is always longer than the load arm.

2. the effort arm is always smaller than the load arm.

3. there is no load

4. the effort arm is always equal to the load arm.

Q. Identify the class I levers in the following.

1. Bottle opener
2. Seesaw
3. Hammer
4. Knife
5. Crowbar
6. Scissors
7. Water pump
8. Nutcracker