Practice Math Problems for Chapter 6

Practice Math Problems for chapter 6 (You need to be able to do these WITHOUT looking at the formula triangles and NO calculators)

1. If an object travels 10 m in 0.5 seconds. What was the object’s speed?

Speed = distance ÷ time

Speed = 10 m ÷ 0.5 s

Speed = 20 m/s

2. If an object travels at 82 m/s how far will it travel in 5.3 seconds? Distance = speed × time

Distance = 82 m/s × 5.3 s

Distance = 434.6 m

3. How long will it take an object to travel 65 m if it is traveling at 4 m/s?

Time = distance ÷ speed

Time = 65 m ÷ 4 m/s Time = 16.25 s 4. If car speeds up from 1.5 m/s to 6.4 m/s in 3 seconds, find the acceleration.

Acceleration = (Velocityf - Velocityi) ÷ time

Acceleration = (6.4 m/s – 1.5 m/s) ÷ 3 s

2 Acceleration = (4.9 m/s) ÷ 3 s = 1.63 m/s

5. An object is dropped. Ignoring air resistance how fast is it moving at the end of 4 seconds?

∆Velocity = gravity x time

∆ velocity = velocityfinal – velocityinitial Vf – Vi = gravity x time

2 Vf – 0 m/s = 9.8 m/s × 4 s

Vf = 39.2 m/s

6. If an object was dropped and is now moving at 29.4 m/s. How long was it falling for?

time = ∆Velocity ÷ gravity

∆ velocity = velocityfinal – velocityinitial Time = (Vf – Vi) ÷ gravity

Time = (29.4 m/s – 0 m/s) ÷ 9.8 m/s

Time = 3 s

7. Find the force necessary to cause a 2.3 kg object to accelerate at 7.2 m/s2.

Force = mass x acceleration Force = 2.3 kg x 7.2 m/s2 Force = 16.56 N

8. If a 15 N force acts on a 4 kg object, what will the objects acceleration be?

Acceleration = Force ÷ mass A = 15 N ÷ 4 kg

A = 3.75 m/s2

9. If a 27 N force causes an object to accelerate at 40.5 m/s2, what was the object’s mass?

Mass = force ÷ acceleration

2 Mass = 27 N ÷ 40.5 m/s

Mass = 0.67 kg

10. An object has 7 kg of mass and is moving 4 m/s. Find momentum. Momentum = mass x velocity P = m x v P = 7 kg x 4 m/s P = 28 kg m/s

11. An object has 51 kg m/s of momentum. If the mass is 17 kg find the velocity of the object.

Velocity = momentum ÷ mass

V = p ÷ m

V = 51 kg m/s ÷ 17 V = 3 m/s

12. An object has 92 kg m/s of momentum. If the velocity of the object is 4 m/s. find the mass of the object.

mass = momentum ÷ velocity

m = p ÷ v

m = 92 kg m/s ÷ 4 m = 23 kg

13. Find the weight of a 50 kg object on earth.

Weight = mass x gravity W = m x g W = 50 kg x 9.8 m/s2 W = 490 N