Correct statement from following is

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2.Motion in Straight Line

easy

The correct statement from the following is

A body having zero velocity will not necessarily have zero acceleration

A body having zero velocity will necessarily have zero acceleration

A body having uniform speed can have only uniform acceleration

A body having non-uniform velocity will have zero acceleration

Solution

(a)When the body is projected vertically upward then at the highest point its velocity is zero but acceleration is not equal to zero $(g = 9.8m/{s^2})$.

Standard 11

Physics

The distance-time graph of a particle at time $t$ makes angle $45^{\circ}$ with the time axis. After one second, it makes angle $60^{\circ}$ with the time axis. What is the average acceleration of the particle?

medium

A monkey climbs up a slippery pole for $3$ and subsequently slips for $3$. Its velocity at time $t$ is given by $v (t) = 2t \,(3s -t)$ ; $0 < t < 3$ and $v(t) =\,-\, (t -3)\,(6 -t)$ ; $3 < t < 6$ $s$ in $m/s$. It repeats this cycle till it reaches the height of $20\, m$.

$(a)$ At what time is its velocity maximum ?

$(b)$ At what time is its average velocity maximum ?

$(c)$ At what time is its acceleration maximum in magnitude ?

$(d)$ How many cycles (counting fractions) are required to reach the top ?

hard

A person sitting in a moving train with his face towards the engine, throws a coin vertically upwards. The coin falls ahead of person. The train:

easy

The acceleration $a$ in $m / s ^2$, of a particle is given by $a=3 t^2+2 t+2$, where $t$ is the time. If the particle starts out with a velocity $v=2 m / s$ at $t=0$, then the velocity at the end of $2\,s$ is $…………m/s$

medium

If the velocity of a body related to displacement ${x}$ is given by $v=\sqrt{5000+24 {x}} \;{m} / {s}$, then the acceleration of the body is $\ldots \ldots {m} / {s}^{2}$