A force $\overrightarrow F = (5\hat i + 3\hat j)$Newton is applied over a particle which displaces it from its origin to the point $\overrightarrow r = (2\hat i - 1\hat j)$ metres. The work done on the particle is..............$J$
$-7$
$+13$
$+7$
$+11$
A bomb of mass $9\, kg$ explodes into two pieces of masses $3\, kg$ and $6\, kg$. The velocity of mass $3\, kg$ is $16\, m/s$. The $KE$ of mass $6\, kg$ (in joule) is
A particle is moved from $(0, 0)$ to $(a, a)$ under a force $\vec F = (3\hat i + 4\hat j)$ from two paths. Path $1$ is $OP$ and path $2$ is $OQP$. Let $W_1$ and $W_2$ be the work done by this force in these two paths respectively. Then
A particle of mass $7\, kg$ moving at $5\, m/s$ is acted upon by a variable force opposite to its initial direction of motion. The variation of force $F$ is shown as a function of time $t$.
A body of mass $m= 10^{-2} \;kg$ is moving in a medium and experiences a frictional force $F= -kv^2$ Its intial speed is $v_0= 10$ $ms^{-1}$ If, after $10\ s$, its energy is $\frac{1}{8}$ $mv_0^2$ the value of $k$ will be
The energy required to accelerate a car from $10 \,m/s$ to $20\, m/s$ is how many times the energy required to accelerate the car from rest to $10\, m/s$