Question

If a net force of 7 N was constantly applied on 400 g object at rest, how long will it take to raise its velocity to 80 m/s?​

Answer 1

Answer:

we know f=mv/t from that 7=400/1000×80/t=4.57s

Answer 2

GiveN :-

• A 7 N was constantly applied on 400 g object at rest .

To FinD :-

• How long will it take to raise its velocity to 80 m/s.

SolutioN :-

Given that a 7 N was constantly applied on 400 g object at rest .We need to find how long will it take to raise its velocity to 80 m/s. So we know the formula of Force as ,

$\red{\bigstar}$ Using the formula of Force :-

$\sf:\implies \pink{ Force = mass \times Acceleration }\\\\\sf:\implies 7N = 400g \times a \\\\\sf:\implies a =\dfrac{7N}{400g}\\\\\sf:\implies a =\dfrac{7N \times 1000}{400 kg } \\\\\sf:\implies \boxed{\pink{\frak{ Acceleration= 17.5 m/s^2}}}$

$\rule{200}2$

Now we need to find the time , so for that use the first equation of motion . Since here we know acceleration , Initial velocity and Final Velocity .

★ Using first equation of motion :-

$\sf:\implies \pink{ v = u + at }\\\\\sf:\implies 80m/s = 0 m/s + 17.5m/s^2\times t \\\\\sf:\implies 17.5t = 80 s \\\\\sf:\implies t =\dfrac{80 s}{17.5}\\\\\sf:\implies \underset{\blue{\sf Required\ Time}}{\underbrace{\boxed{\pink{\frak{ Time = 4.57 \ seconds}}}}}$