Question

an object with a mass of 10kg moves at a constant velocity of 10m/s. A constant force then acts for 4 sec on the object and gives it a speed of 2m/sec in opposite direction. The force produced in it is,

Answer 1

Given

• Mass = 10 kg
• Initial Velocity = 10 m/s
• Time = 4 sec
• Final Velocity = 2 m/s

To Find

• Force Applied

Solution

● v = u + at [First Equation of Motion]

● F = ma

✭ Acceleration :

→ v = u + at

→ 2 = 10 + a × 4

→ 2-10 = 4a

→ -8 = 4a

→ -8/4 = a

→ Acceleration = -2 m/s²

━━━━━━━━━━━━━━━━━━

✭ Force Applied :

→ F = ma

→ F = 10 × (-2)

→ F = -20 N

• Here the force is -ve because the force is applied in the opposite direction of the motion

Answer 2

Answer:

Given :-

• An object with a mass of 10 kg moves at a constant velocity of 10 m/s. A constant force acts for 4 seconds on the object and gives it a speed of 2 m/s in opposite direction.

To Find :-

• What is the force produce.

Formula Used :-

❖ a = v - u/t ❖

✦ F = ma ✦

where,

• v = Final velocity
• u = Initial velocity
• a = Acceleration
• t = Time
• F = Force
• m = Mass

Solution :-

Given to find acceleration,

• u = 10 m/s
• v = 2 m/s
• t = 4 second

According to the question by using the formula we get,

⇒ a = 2 - 10/4

⇒ a = - 8/4

➠ a = - 2 m/s

Now, we have to find the force,

We get,

• m = 10 kg
• a = - 2 m/s

According to the question by using the formula we get,

↦ F = 10 × - 2

➦ F = - 20 N

∴ The force produce on an object is - 20 N .