a body is moving with a speed of 20 metre per second when create in force is applied and acceleration of 4 metre per second square is produced after who much time its velocity will be 80 metre per second
Answers
Answer:
15 sec
Explanation:
According to the given question,
v = final velocity = 80 m/s
u = initial velocity = 20 m/s
a = acceleration = 4 m/s^2
t = time
And we are asked to find the time of the body by which it attains final velocity of 80 m/s.
We know,
- v = u+at
Putting the values we get,
- 80 = 20 + 4t
- 4t = 80-20
- 4t = 60
- t = 60/4
- t = 30/2
- t = 15 sec
Thus body will take 15 sec to have its velocity of 80 m/s with acceleration of 4 m/s^2 and initial velocity, 20 m/s.
ANSWER!
Kinematical equations:
As the units of all the mentioned quantities are in the same system i.e C. G. S system we don't need to change the units of the quantities.
Given:
initial velocity (u) = 20m/s
acceleration (a) = 4m/s²
final velocity (v) = 80m/s
To find: Time taken to gain a velocity of 80m/s by the body.
Using the first kinematical equation
v = u + at
Substitute the values of the quantities in the above formula,
80 = 20 + 4×t
80 = 20 + 4t
80 - 20 = 4t
60 = 4t
t = 60/4
÷ by 2
t = 30/2
÷ by 2
t = 15
.°. time (t) = 15 seconds.
Hence, the time required by the body to attain a velocity of 80m/s with an acceleration of 4m/s² is 15 seconds.