Momentum word problems

The momentum word problems  will use the formula you see below when calculating the momentum. 

momentum = mv

m is the mass and v is the velocity or speed.

The mass must be in kg  and the speed must be in m/s or meter per second.

Word Problem # 1:

Calculate the momentum when a 10-kg object move with a speed of 5 m/s


momentum = 10 kg × 5 m/s = 50 kg.m/s

 Challenging momentum word problems

Word Problem #2:

The momentum of a bus with a mass of 10000 kg is 200000 kg.m/s. How far can bus go if the bus maintain the same speed for 5 minutes and then stop?


First, we need to find the speed of the bus by using the formula

momentum = mass × v

200000  = 10000 × v

Since 10000 × 20 = 200000, v = 20

The speed of the bus is 20 m/s

If the car does 20 meters per second, it will do 20 × 60 meters = 1200 meters in 1 minute. 

If the car does 1200 meters in 1 minute, it will 1200 × 5 meters = 6000 meters in 5 minutes.

6000 meters  = 6 kilometers = 3.73 miles

The bus will do about 3.73 miles before it stops.

Word Problem # 3:

An 200-kg man moving with a speed of 1 meter per second has the same momentum as a smart car moving with a speed of 0.25 m/s. How much does the smart car weight in pounds?


The momentum of the 200-kg man is 200 kg × 1 m/s = 200 kg.m/s

The momentum of the smart car is mass × 0.25 m/s

Since the momentum of the man is equal to the momentum of the smart car, we get

200 kg.m/s = mass × 0.25 m/s

mass =
200 kg.m/s / 0.25 m/s

mass = 800 kg

The weight in pound is 800 kg × 2.2 = 1760 pounds

Word Problem # 4:

A man with a mass of 100 kg has a momentum of 200 kg.m/s. He decides now to wear a backpack that has a weight of 25 kg to challenge himself. If he can keep up the same speed when he is wearing the backpack, by how much will his momentum increase?


Momentum = mass × speed

200  = 100 × speed

Since 100 times 2 = 200, speed  = 2 m/s

Now the total mass is 100 kg + 25 kg = 125 kg.

If he can still run with the sqme speed of 2 m/s, his momentum is 

125 kg × 2 m/s = 250 kg.m/s

His momentum is increase by 50 kg.m/s  (250 - 200 kg.m/s)

Hopefully, the momentum word problems on this page really helped you to see how to calculate the momentum. 

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