Question 1 :
A force {tex} F _ { x } {/tex} acts on a particle such that its position {tex} x {/tex} changes as shown in the figure. The work done by the particle as it moves from {tex} x = 0 {/tex} to {tex} 20 \mathrm { m } {/tex} is<br><img style='object-fit:contain' src="https://storage.googleapis.com/teachmint/question_assets/NEET/5e0ee5a88420d95285473c0c">

Question 2 :
A cord is used to raise a block of mass $m$ vertically through a distance $d$ at a constant downward acceleration $g/4$. The work done by the cord is:

Question 3 :
The force required to row a boat over the sea is proportional to the speed of the boat. If it is found that it takes $24$ h.p. to row a certain boat at a speed of $8\: km/hr$, then the horsepower required when speed is doubled is :

Question 4 :
A force $F = (5 \hat {i} + 3\hat {j})$ newtons is applied over a particle which displaces it from its origin to the point $r = (2\hat {i} - 1\hat {j})$ metres. The work done on the particle is

Question 5 :
A particle moves with a velocity $\vec v=(5\hat i-3\hat j+6\hat k) ms^{-1}$ under the influence of a constant force $\vec F=(10\hat i+10\hat j+20\hat k)N$. The instantaneous power applied to the particle is

Question 7 :
Write true or false for the following statements:<br>In order to get minimum work, the angle between force and displacement should be 90.

Question 8 :
A rigid body of mass m is moving in a circle of radius r with a constant speed v.The force on the body is $\displaystyle \frac{mv^2}{r}$ and is directed towards the centre. What is the work done by this force in moving the body over half the circumference of the circle.

Question 9 :
A uniform force of ($3\hat{i}+\hat{j}$) newton acts on a particle of mass 2 kg. Hence the particle is displaced from position $(2\hat{i}+\hat{k})$ meter to position $(4\hat{i}+3\hat{j}-\hat{k})$ meter. The work done by the force on the particle is

Question 10 :
A force applied by an engine of a train of mass $ 2.05 \times 10^6 \quad kg $ changes it velocity from $ 5 m /s $ to $ 25 m/s $ in $ 5$ minutes . the power of engine is