Question

Q 3/80 A body is moving with a speed
of 20 m/s. When certain force is
applied, an acceleration of 4
m/s2
is produced. After how much time its
velocity will be 80 m/s​

Answer 1

Answer:

Explanation:

Given :-

Initial velocity, u = 20 m/s

Acceleration, a = 4 m/s²

Final velocity, v = 80 m/s

To Find :-

Time taken, t = ??

Formula to be used :-

1st equation of motion,

i.e, v = u + at

Solution :-

Putting all the values, we get

v = u + at

⇒ 80 = 20 + 4 × t

⇒ 80 - 20 = 4t

⇒ 60 = 4t

⇒ 60/4 = t

⇒ t = 15 seconds

Hence, the time taken by body is 15 seconds.

Answer 2

Answer:

15 seconds

Explanation:

Given:

• Initial velocity of the body = u = 20 m/s
• Acceleration produced in the body = a = 4 m/s²
• Final velocity of the body = v = 80 m/s

To find:

• Time required to make the final velocity equal to 80 m/s = t

By using the first equation of motion which says:

V=u+at

Where:

V = final velocity

u = initial velocity

a = acceleration

t = time

Substituting the above values, we get:

80=20+4×t

80-20=4t

60=4t

t = $\frac{60}{4}$

t = 15 seconds

The time taken for the body to move with a velocity of 80 m/s is equal to 15 seconds