2<span>cos2(θ)−1 = 0
</span><span>2cos2(θ)=1
</span><span>cos2(θ)=1/2
</span><span>2θ=arc cos1/2
</span><span>2θ=60 degrees
</span><span>θ=30 degrees</span>
7.89•10 to the third power
1. An 8-kilogram bowling ball is rolling in a straight line toward you. If its momentum is 16 kg•m/s, how fast is it traveling?
momentum = mass x velocity
16 = 8 x velocity
velocity = 2 m/s
2.A beach ball is rolling in a straight line toward you at a speed of 0.5 m/sec. Its momentum is 0.25 kg•m/s. What is the mass of the beach ball?
momentum = mass x velocity
0.25 = m x 0.5
mass = 0.5 kg
3.A 4,000-kilogram truck travels in a straight line at 10.0 m/s. What is its momentum?
Momentum = (mass) x (speed) = (4,000) x (10) = 40,000 kilogram-meters/second
4.A 1,400-kilogram car is also traveling in a straight line. Its momentum is equal to that of the truck in the previous question. What is the velocity of the car?
40,000 kilogram-meters/second = 1400 x velocity
velocity = 28.6 m/s
5.Which would take more force to stop in 10 seconds: an 8.0-kilogram ball rolling in a straight line at a speed of 0.2 m/s or a 4.0-kilogram ball rolling along the same path at a speed of 1.0 m/s?
F1 = 8 x 0.2 / 10 = 0.16 N
F2 = 4 x 1.0 / 10 = 0.4 N ----> take more force
6.The momentum of a car traveling in a straight line at 20 m/s is 24,500 kg•m/s. What is the car’s mass?
24500 = mass x 20
mass = 1225 kg
7.Another pitcher throws the same baseball in a straight line. Its momentum is 2.1 kg•m/s. What is the velocity of the ball?
2.1 = 0.5 x velocity
velocity = 4.2 m/s
8 A 1-kilogram turtle crawls in a straight line at a speed of 0.01 m/s. What is the turtle’s momentum?
momentum = 1 x 0.01 = 0.01 kg m/s
Judging by the density (19.3 g/ml) there's a very good chance that it could be gold.
Density = mass/volume. 5000/50= 100 grams per cubic centimeter. No substance on Earth has anywhere near that density. Tops is about 20 for osmium and gold.
