Advertisements
Advertisements
प्रश्न
Derive the formula : v = u + at, where the symbols have usual meanings.
Advertisements
उत्तर
Consider a body has initial velocity (u) . Suppose it is subjected to a uniform acceleration (a) such that after time (t) its final velocity becomes (v). Now, from the definition of acceleration we know that:
Acceleration = `"Change in velocity"/"Time taken"`
The above expression can also be written as ,
`a = (v-u)/t`
On further simplification, we get the 1st equation of motion,
v = u + at
Where,
(a) - Acceleration
(v) - Final velocity
(u) - Initial velocity
(t) - Time taken
The equation v = u + at is called the first equation of motion and is used to calculate the velocity 'v' acquired by a body in time 't'.
APPEARS IN
संबंधित प्रश्न
A bus decreases its speed from 80 km h−1 to 60 km h−1 in 5 s. Find the acceleration of the bus.
Fill in the following blank with suitable word :
A motorcycle has a steady……………. of 3 m/s2. This means that every………………. its…………….. increases by………….
What is meant by the term acceleration ? State the SI unit of acceleration.
What conclusion can you draw about the velocity of a body from the displacement-time graph shown below :
Describe the motion of a body which is accelerating at a constant rate of 10 m s–2. If the body starts from rest, how much distance will it cover in 2 s ?
A bus running at a speed of 18 km/h is stopped in 2.5 seconds by applying brakes. Calculate the retardation produced.
A bicycle initially moving with a velocity 5.0 m s-1 accelerates for 5 s at a rate of 2 m s-2. What will be its final velocity?
The figure shows the displacement - time graph for four bodies A, B C and D. In each case state what information do you get about the acceleration (zero, positive or negative).
The velocity-time graph of a body in motion is a straight line inclined to the time axis. The correct statement is ___________
When is the positive acceleration?
