Free Body Diagram

Q. A block of mass 2kg is placed on the floor.The coefficient of static friction between the two surfaces is 0.4 . A horizontal force of 2.5N is applied on the block . The force of friction between the block and the floor is ?

Q.

Find the effort required to lift a load of $50kgwt$ using a simple machine.

Q.

A fielder pulls his hands gradually with the moving ball while holding a catch. Why does he do this?

1. It reduces the frictional forces between hand and the ball

2. It reduces the impact of catching the fast moving ball.

3. It increases the momentum of the ball.

4. none

Q.

Frictional force on a body can be zero when

1. normal reaction is equal to zero

2. the body is moving in vaccum

3. the body is moving through a liquid

4. all of these

Q.

Ratio of force of limiting friction to normal reaction is?

Q. Why is rolling a cylinder easier than pushing a cube of the same mass and same material?

Q.

If we hit the ground with a ball it bounces back because of Newton's third law. Then why it stops bouncing after sometime?

Q.

why does ball bounce when we throw the ball on ground even when gravitational force is acting on it.

Q.

A force of$5N$ acts on a body of weight $9.8N$. What is the acceleration produced in $m/s^2$?

1. $49$

2. $5$

3. $1.46$

4. $0.51$

Q.

What is the difference between force and pressure

Q.

Does atmospheric pressure affect vapour pressure?

Q.

A monkey of mass $40kg$ climbs on a rope. The rope can stand a maximum tension of $600N$. In which of the following cases will the rope break:

1. climbs up with an acceleration of $6m{s}^{-2}$

2. climbs down with an acceleration of $4m{s}^{-2}$

3. climbs up with a uniform speed of $5m{s}^{-1}$

4. falls down the rope nearly freely under gravity

Q.

Three masses 5 kg, 4 kg and 7 kg are aligned in a straight line as shown below. Find the net gravitational force on 4 kg.

1. Zero

2. 33.5 N

3. 13.19 N

4. 46.69 N

Q.

What is tension force?

Q.

Calculate the effort needed when load arm = 50 m, effort arm = 125 m and load = 100 kg wt

Q.

Is it possible that a force changes only in the direction of motion without any change in the speed of the object.​​​​ illustrate your answer with example.

Q. Why does a moving swing move faster when pushed by a person?

Q.

Calculate the force required to compress a spring by $50cm$, if the spring contant (k) $=10N/m$.

1. $15N$

2. $25N$

3. $3N$

4. $5N$

Q. Question 2
In the figure, a boy is shown pushing the box from right to left. The force of friction will act on the box.


(a) from right to left $(\leftarrow )$
(b) from left to right $(\to )$
(c) vertically downwards $(\downarrow )$
(d) vertically upwards $(\uparrow )$

Q.

what is force and pressure? what is the relation between joule and newton?

Q.

A block of mass $10kg$ is held against a vertical wall by applying a horizontal force of $50N$.The coefficient of friction is 0.2 between the block and the wall. What is the frictional force acting? (Take acceleration due to gravity, $g=10m/s^2$)

1. 104 N

2. 10 N

3. 30 N

4. 80 N

Q. An object of mass 0.5 kg is whirled at the end of a string 0.8m long. If the string makes 3 revolution in 1.2 sec find the tension in the string

Q. According to Newton's universal Gravitational laws, any two object that have masses exerts gravitational force but why.

Q.

What is vector

Q.

Repected sir,

I had a doubt on force and pressure numericals. The numerical down.

Two blocks of different metals but identical in shape and size are acted upon by equal forces such that the acceleration of the second block is 3 times more than that of first block. What is the ratio of the mass of the second block respect to the first block.

Q. State the laws of motion.

Q.

A block of mass $m$ is resting on a horizontal surface. The coefficient of friction is 0.4. A horizontal force of $10N$ is needed to move the block. Normal reaction $N$ acting is

1. $50N$

2. $125N$

3. $5N$

4. $25N$

Q.

Which of the following is an example of negative acceleration?

1. Rocket landing
2. A ball thrown upwards
3. Hitting a ball on the wall
4. Bunjee jumping

Q. Give various examples to show that friction is both a friend and a foe. [3 MARKS]

Q. The ratio of the weight of a man in a stationary lift and when it is moving downward with uniform acceleration ${}^{\prime }{a}^{\prime }$ is $3:2$. The value of ${}^{\prime }{a}^{\prime }$ is (g-Acceleration due to gravity on the earth).

1. $g$
2. $\frac{g}{3}$
3. $\frac{3g}{2}$
4. $\frac{2g}{3}$