Laws Of Motion - Mechanics - Physics Previous Year Questions

If a string, suspended from the ceiling is given a downward force F₁, its length becomes L₁. Its length is L₂, if the downward force is F₂. What is its actual length?

A golf ball of mass 50 gm placed on a tee, is struck by a golf-club. The speed of the golf ball as it leaves the tee is 100 m/s, the time of contact on the ball is 0.02 s. If the force decreases to zero linearly with time, then the force at the beginning of the contact is

A body of mass 2 kg moves in a horizontal circular path of radius 5 m. At an instant, its speed is 2\(\sqrt5\) m/s and is increasing at the rate of 3 m/s\(^2\). The magnitude of force acting on the body at that instant is,

What force \(\mathrm{F}\) is required to start moving this \(10 \mathrm{~kg}\) block shown in the figure if it acts at an angle of \(60^{\circ}\) as shown? \((\mu_s=0.6)\)

Two spheres $S_1$ and $S_2$ of masses $m_1$ and $m_2$ respectively collide with each other. Initially $S_1$ is at rest and $S_2$ is moving with velocity $v$ along $x$-axis. After collision $S_2$ has a velocity $\frac{v}{2}$ in a direction perpendicular to the original direction. The sphere $S_1$ moves after collision

A force $\vec{F}=a \hat{i}+b \hat{j}+c \hat{k}$ is acting on a body of mass $m$. The body was initially at rest at the origin. The co-ordinates of the body after time ' $t$ ' will be

The minimum force required to start pushing a body up a rough (having co-efficient of friction $\mu$ ) inclined plane is $\vec{F}_1$ while the minimum force needed to prevent it from sliding is $\overrightarrow{F_2}$. If the inclined plane makes an angle $\theta$ with the horizontal such that $\tan \theta=2 \mu$, then the ratio $F_1 / F_2$ is

When a ball of mass 5 kg hits a bat with a velocity $3 \mathrm{~m} / \mathrm{s}$, in positive direction and it moves back with a velocity $4 \mathrm{~m} / \mathrm{s}$, find the impulse in SI units.

A shell of mass 10 kg is moving with a velocity of 10 ms^\(-\)1 when it blasts and forms two parts of mass 9 kg and 1 kg respectively. If the 1st mass is stationary, the velocity of the 2nd is

Force required to move a mass of 1 kg at rest on a horizontal rough plane (\(\mu\) = 0.1 and g = 9.8 m/s²) is

A bullet emerges from a barrel of length 1.2 m with a speed of 640 ms^\(-\)1. Assuming constant acceleration, the approximate time that it spends in the barrel after the gun is fired is

A rocket of mass 100 kg burns 0.1 kg of fuel per sec. If the velocity of exhaust gas is 1 km/sec, then it lifts with an acceleration of

Three blocks of masses $m_1=2 \mathrm{~kg}, m_2=3 \mathrm{~kg}$ and $m_3=5 \mathrm{~kg}$ are placed on a horizontal frictionless surface and a force of 30 N pulls the system as shown below．The value of tension $T$ will be