Finding Distance Traveled with Varying Acceleration

[vipulgoyal]

Homework Statement

a motor drives a body along a straight line with a constant force. The power P delivered by the motor must vary with time t according to?
where t is time and conditions are ideal

Homework Equations

P = F v
x=vt

The Attempt at a Solution

according to me answer comes as t^-1 but as you know that's not the answer is t just that

 

[Bhumble]

Your question is unclear.

 

[I like Serena]

a motor drives a body along a straight line with a constant force. The power P delivered by the motor must vary with time t according to?
where t is time and conditions are ideal

P=Fv, where F is constant, so P must vary with time according to v.

 

[vipulgoyal]

P=Fv, where F is constant, so P must vary with time according to v.

i felt the same when i read the question

 

[vipulgoyal]

Homework Statement

a point initially at rest moves along x-axis its accelaration varies with time as a= 6t+5 if it starts from the origin the distance covered in 2s is

Homework Equations

s= ut +1/2at²

The Attempt at a Solution

ijus tried put the values of different variable in the equation but the answer doesnot come that way is their any prob with it??

 

[I like Serena]

i felt the same when i read the question

Actually we can say a bit more.
Under ideal conditions I assume the friction is zero.

That means:

$$a = \frac F m$$

$$v = a t = \frac F m t$$

$$P = F v = \frac {F^2} m t$$

So P varies linearly with t.

 

[I like Serena]

Homework Statement

a point initially at rest moves along x-axis its accelaration varies with time as a= 6t+5 if it starts from the origin the distance covered in 2s is

Homework Equations

s= ut +1/2at²

The Attempt at a Solution

ijus tried put the values of different variable in the equation but the answer does not come that way is their any prob with it??

Your equation only holds when a is constant.

You need the following equations:

$$\begin{equation}v(t) = \int_0^t a(t) dt \label{eq:a_integral}\end{equation}<br /> \begin{equation}s(t) = \int_0^t v(t) dt \label{eq:v_integral}\end{equation}$$