Question

Velocity of the object of mass 10 kg increases from 18 m/s to 36 m/s. A constant force acts on the object for 2 seconds. Find its force. What will be the force for time 4 seconds?​

Answer 1

Answer:

A constant force acts on an object of mass 5 kg for a duration of 2 seconds .It increases the objects velocity from 3 m/s to 7 m/s. Find the magnitude ...

Answer 2

Given :

• mass of object = 10 kg
• Initial velocity = 18 m/s
• Final velocity = 36 m/s
• Time in 1st case = 2 s
• Time in 2nd case = 4 s

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To find :

Find the force acting on the body in :

1] case one : time 2s

2] case two : time 4s

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Formula to be applied :

• Force = m×a
• Force = m×(v-u)/t

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Solution :

1] case 1 :

Given, mass = 10 kg

Initial velocity = 18 m/s

Final velocity = 36 m/s

Time = 2s

$\implies \tt{f = m \times \frac{v - u}{t} }$

$\implies \tt{f = 10 \times \frac{36 - 18}{2} }$

$\implies \tt{f = 5 \times 18}$

$\red{\underline{ \boxed{ { \tt{ \therefore \: force = 90 \: n}}}}}$

Hence, Force = 90 N

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2] Case 2 :

given, mass = 10 kg

Initial velocity = 18m/s

Final velocity = 36 m/s

Time = 4 s

$\implies \tt{f = m \times \frac{v - u}{t} }$

$\implies \tt{f = 10 \times \frac{36 - 18}{4} }$

$\implies \tt{f = 10 \times \frac{18}{4} }$

$\implies \tt{f = 10 \times 4.5}$

$\red{ \underline{ \boxed{ \tt{ \therefore \: force = 45 \: n}}}}$

Hence, Force = 45 N

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Additional information:

• Force = mass × acceleration
• Force = m(v-u)/t
• Force = (mv-mu)/t

(This means , Force can also be found out if the final and the initial momentum are known . )

• Momentum = mass×velocity
• Impulse = Force×time
• Pressure = Force/area
• Pressure (hydrostatic) = Density×gravity×Depth