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
<span>C) Both rocks strike the water at the same time.</span>
I think It would be C. Checking a prediction. Sorry if I’m wrong
Answer:
7800kg/m³
Explanation:
Density of iron in CGS unit is 7.8 g/cm3. Its density is SI is
Given the density of iron = 7.8 g/cm3.
The SI units must be in kg/m³
7.8g = 7.8/1000 kg
7.8g = 0.0078kg
1cm³ = 0.000001m³
7.8g/cm³
= 0.0078/0.000001 kg/m³
= 7800kg/m³
Hence the density in SI unit is 7800kg/m³
After reading this whole question, I feel like I've already
earned 5 points !
-- Two satellites at the same distance, different masses:
The forces of gravity between two objects are directly
proportional to the product of the objects' masses. In
other words, the gravitational forces between the Earth
and an object on its surface are proportional to the mass of
the object. In other words, people with more mass weigh more
on the Earth, and the Earth weighs more on them.
If the satellites are both at the same distance from Earth,
then the Earth pulls on the one with more mass with greater
force, and also the one with more mass pulls on the Earth
with greater force.
-- Two satellites with the same mass, at different distances:
The forces of gravity between two objects are inversely
proportional to the square of the distance between them.
In other words, the gravitational
forces between the Earth
and an object are inversely proportional
to the square of
the distance between the object and the center of the Earth.
If
the satellites both have the same mass, then the Earth
pulls on the nearer one with greater force, and also the
nearer one pulls on the Earth with greater force.
-- Resistor in a circuit when the voltage changes:
The resistance depends on how the resistor was manufactured.
Its resistance is marked on it, and doesn't change. It remains
the same whether the voltage changes, the current changes,
the time of day changes, the cost of oil changes, etc.
If you increase the voltage in the circuit where that resistor is
installed, the current through the resistor increases. If the current
remains constant, then you can be sure that somebody snuck over
to your circuit when you weren't looking, and they either installed
another resistor in series with the original one to make the total
resistance bigger, or else they snipped the original one out of the
circuit and quickly connected one with more resistance in its place.
