At a place where the acceleration due to gravity is 10msec ? a force of 5 kg-wt acts on a body of mass 10
kg initially at rest. The velocity of the body after 4 second is
(A) 5msec)
(B) 10msec
(C) 20msec-1
(D) 50msec
Answers
☯ Velocity at 4s = 20m/s …..[C]
Given ,
- Acceleration due to gravity (g) = 10m/s²
- Force = 5kgWt
- Mass = 10kg
We need to find ,
- Velocity after 4s = ?
So , by the given information, since the body starts from rest , it's initial velocity (u) will be zero and force will be 50N because, 5kgwt = 5N. Finding velocity using first equation of motion .
◉ v = u + at
Here , in the given question ,they didn't give the acceleration in horizontal motion , so a = F/M = 50/10 = 5m/s².
So , now
⇢ v = u + at
⇢ v = 0 + 5 × 4
⇢ v = 0 + 20
⇢ Velocity = 20 m/s
Given :-
- Acceleration (a) = 10 m/s²
- Force (f) = 5kg wt
- Mass (m) = 10 kg
- Initial Velocity (u) = 0 [Body was initially at rest]
- Time (t) = 4 sec
To Find :-
- Velocity of the body after 4 second = ?
Concept Implemented :-
✰ Equations of Motion
❶ First Equation of Motion
v = u + at
❷ Second Equation of Motion
s = ut + ½at²
❸ Third Equation of Motion
v² = 2as + u²
✰ Force = Mass × Acceleration
✰ F = ma
✰ 1 kg-Weight = 9.8 N
✰ 1 kg-Weight ≈ 10 N
Solution :-
◆ Let's first change the force from kg wt to N.
⌦ 1 kg wt = 10 N
⇒ 5 kg wt = 5 × 10 N
⇒ 5 kg wt = 50 N
∴ Force = 50 N
⌦ Force = Mass × Acceleration
⇒ 50 N = 10kg × Acceleration
⇒ 50/10 = Acceleration
⇒ 5 m/s² = Acceleration
⇒ Acceleration = 5 m/s²
∴ Acceleration = 5 m/s²
◆ Now we use First Equation of Motion
⌦ v = u + at
⇒ v = 0 + (5 × 4)
⇒ v = 0 + 20
⇒ v = 20 m/s
∴ v = 20 m/s
∴ The velocity of the ball after 4 seconds is 20 m/s.
Hence Option 【C】is correct. ✅
Learn More from Brainly :-
A stone thrown from the top of a building is given an initial velocity of m/s straight upward determine the time in second at which the stone reaches its maximum height. (Take g = 9.8 m/s²)
See answer at:
https://brainly.in/question/33630388