HARD

JEE Main

IMPORTANT

Earn 100

A body of mass $m$ was slowly hauled up the hill by a force $\vec{F}$ which at each point was directed along a tangent to the trajectory. Find the work performed by this force, if the height of the hill is $h$ , the length of its base $l$ , and the coefficient of friction is $k$ .

Important Questions on PHYSICAL FUNDAMENTALS OF MECHANICS

HARD

JEE Main

IMPORTANT

Problems in General Physics>Chapter 1 - PHYSICAL FUNDAMENTALS OF MECHANICS>LAWS OF CONSERVATION OF ENERGY, MOMENTUM, AND ANGULAR MOMENTUM>Q 1.122.

A disc of mass

m = 50 g

slides with the zero initial velocity down an inclined plane set at an angle

α = 30 °

to the horizontal; having traversed the distance

l = 50 cm

along the horizontal plane, the disc stops. Find the work performed by the friction forces over the whole distance, assuming the friction coefficient

k = 0.15

for both inclined and horizontal planes.

HARD

JEE Main

IMPORTANT

Problems in General Physics>Chapter 1 - PHYSICAL FUNDAMENTALS OF MECHANICS>LAWS OF CONSERVATION OF ENERGY, MOMENTUM, AND ANGULAR MOMENTUM>Q 1.123.

Two bars of masses

m_{1}

and

m_{2}

connected by a non-deformed light spring rest on a horizontal plane. The coefficient of friction between the bars and the surface is equal to

k

. What minimum constant force has to be applied in the horizontal direction to the bar of mass

m_{1}

in order to shift the other bar?

HARD

JEE Main

IMPORTANT

Problems in General Physics>Chapter 1 - PHYSICAL FUNDAMENTALS OF MECHANICS>LAWS OF CONSERVATION OF ENERGY, MOMENTUM, AND ANGULAR MOMENTUM>Q 1.124.

A chain of mass

m = 0.80 kg

, and length

l = 1.5 m

rests on a rough-surfaced table so that one of its ends hangs over the edge. The chain starts sliding off the table all by itself provided the overhanging part equals

η = \frac{1}{3}

of the chain length. What will be the total work performed by the friction forces acting on the chain by the moment it slides completely off the table?

HARD

JEE Main

IMPORTANT

Problems in General Physics>Chapter 1 - PHYSICAL FUNDAMENTALS OF MECHANICS>LAWS OF CONSERVATION OF ENERGY, MOMENTUM, AND ANGULAR MOMENTUM>Q 1.125.

A body of mass

m

is thrown at an angle

α

to the horizontal with the initial velocity

v_{0}

. Find the mean power developed by gravity over the whole time of motion of the body, and the instantaneous power of gravity as a function of time.

HARD

JEE Main

IMPORTANT

Problems in General Physics>Chapter 1 - PHYSICAL FUNDAMENTALS OF MECHANICS>LAWS OF CONSERVATION OF ENERGY, MOMENTUM, AND ANGULAR MOMENTUM>Q 1.126.

A particle of mass

m

moves along a circle of radius

R

with a normal acceleration varying with time as

w_{n} = a t^{2}

, where

a

is a constant. Find the time dependence of the power developed by all the forces acting on the particle, and the mean value of this power averaged over the first

t

seconds after the beginning of motion.

HARD

JEE Main

IMPORTANT

Problems in General Physics>Chapter 1 - PHYSICAL FUNDAMENTALS OF MECHANICS>LAWS OF CONSERVATION OF ENERGY, MOMENTUM, AND ANGULAR MOMENTUM>Q 1.127.

A small body of mass $m$ is located on a horizontal plane at the point $O$ . The body acquires a horizontal velocity $v_{0}$ . Find,

$(a)$ The mean power developed by the friction force during the whole time of motion, if the friction coefficient $k = 0.27, m = 1.0 kg$ , and $v_{0} = 1.5 m s^{- 1}$ ,

$(b)$ The maximum instantaneous power developed by the friction force, if the friction coefficient varies as $k = α x$ , where $α$ is a constant, and $x$ is the distance from the point $O$ .

HARD

JEE Main

IMPORTANT

Problems in General Physics>Chapter 1 - PHYSICAL FUNDAMENTALS OF MECHANICS>LAWS OF CONSERVATION OF ENERGY, MOMENTUM, AND ANGULAR MOMENTUM>Q 1.128.

A small body of mass

m = 0.10 kg

moves in the reference frame rotating about a stationary axis with a constant angular velocity

ω = 5.0 rad s^{- 1}

. What work does the centrifugal force of inertia perform during the transfer of this body along an arbitrary path from point

1

to point

2

which are located at the distances

r_{1} = 30 cm

and

r_{2} = 50 cm

from the rotation axis?

HARD

JEE Main

IMPORTANT

Problems in General Physics>Chapter 1 - PHYSICAL FUNDAMENTALS OF MECHANICS>LAWS OF CONSERVATION OF ENERGY, MOMENTUM, AND ANGULAR MOMENTUM>Q 1.129.

A system consists of two springs connected in series and having the stiffness coefficients

k_{1}

and

k_{2}

. Find the minimum work to be performed in order to stretch this system by

Δ l

A body of mass m was slowly hauled up the hill by a force F→ which at each point was directed along a tangent to the trajectory. Find the work performed by this force, if the height of the hill is h, the length of its base l, and the coefficient of friction is k.

Important Questions on PHYSICAL FUNDAMENTALS OF MECHANICS

Learn and Prepare for any exam you want !

A body of mass $m$ was slowly hauled up the hill by a force $\vec{F}$ which at each point was directed along a tangent to the trajectory. Find the work performed by this force, if the height of the hill is $h$ , the length of its base $l$ , and the coefficient of friction is $k$ .