Question

A car accelerates at a rate of 4.0 m/s2. if its original speed is 7.0 m/s how many seconds will it take to reach 30.0 m/s

Answer 1

Answer:

5.75 secs

Explanation:

u=7

v=30

a=4

v=u+at

30=7+4t

4t=23

t=5.75

Answer 2

The question says that the car is currently moving with the speed of 7 m/s and it's acceleration is 4 m/s², so how much time is required to reach the speed of 30 m/s

Given :-

• Initial Velocity (u) = 7 m/s
• Final Velocity (v) = 30 m/s
• Acceleration (a) = 4 m/s²

To Find :-

• Time Taken (t) = ?

What to do?

We have v, u & a, so by the first equation of motion we can simply get the time t.

SoluTion :-

Formula Used :-

• v = u + at

Subsituting Values

→ 30 = 7 + 4 × t

→ 30 = 7 + 4t

→ 30 - 7 = 4t

→ 23 = 4t

→ t = 23/4

→ t = 5.75

So, the time taken is 5.75 second