Question

A car of mass 1000kg is accelerating at 2m/s Square. If the resistance to the motion is 1000N, What is the force due to engine?​

Answer 1

Answer : 3000 N

Forces acting on the car are,

• Weight (downward)
• Normal reaction by the road (upward)
• Force by engine (Forward)
• Resistance (backward)

We are supposed to deal with horizontal forces.

Since the car accelerates with 2 m/s^2.

Therefore,

$F_{net} = m.a \\ = > F_{net} = 1000 \times 2 \\ = > F_{net} =2000 \: newtons$

For the car to accelerate at the rate of 2 m/s^2 the Net Force acting on it should be 2000 N.

Hence,

$Force \: by \: engine + Force \: of \: friction = Net \: Force$

Here, Force by friction(resistance) is in opposite direction,

So, f = - 1000 N

Therefore,

$F_{engine} + F_{resistance } = 2000 \\ = > F_{engine} + ( - 1000) = 2000 \\ = > F_{engine} = 2000 + 1000$

$= > F_{engine} = 3000$

Hope this helps.