Question

A constant force of 50N is applied to a body of 20 kg, which is initially at rest. Find its velocity after 4 seconds of its motion.

Answer 1

Answer:

10m/s

Explanation:

F=50N,m=20kg,u=0,t=4secs

we know that f=ma,so a=f/m

a=50/20=2.5m/s2

and v=u+at,

v =0+2.5×4

=10m/s

Answer 2

Answer- The above question is from the chapter 'Force and Laws of Motion.

Force is a push or a pull.

The SI unit of Force is newton and is named after Isaac Newton, a great scientist. Its symbol is N.

Concept used: 1) Force (F) = Mass (m) × Acceleration (a)

2) a = $\frac{v \: - \: u}{t}$

Here, u = initial velocity of a body

v = final velocity of a body

t = time taken

Given question: A constant force of 50 N is applied to a body of 20 kg, which is initially at rest. Find its velocity after 4 seconds of its motion.

Answer: Force (F) = 50 N

Mass of body (m) = 20 kg

Initial velocity (u) = 0 m/s

Time (t) = 4 s

Final velocity (v) = ?

We know that F = ma

50 = 20 × a

a = 2.5 m/s²

Now, a = $\frac{v \: - \: u}{t}$

2.5 = $\frac{v - 0}{4}$

v = 2.5 × 4

v = 10 m/s

∴ Velocity of the body after 4 seconds of its motion = 10 m/s.