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
Answer:
Explanation:
Two straight wires
Have current in opposite direction
i1=i2=i=2Amps
Distance between two wires
r=5mm=0.005m
Length of one wire is ∞
Length of second wire is 0.3m
Force between the wire,
The force between two parallel currents I1 and I2, separated by a distance r, has a magnitude per unit length given by
F/l = μoi1i2/2πr
F/l=μoi²/2πr
μo=4π×10^-7 H/m
The force is attractive if the currents are in the same direction, repulsive if they are in opposite directions.
F/l = μoi1i2/2πr
F/0.3=4π×10^-7×2²/2π•0.005
F/0.3=1.6×10^-4
Cross multiply
F=1.6×10^-4×0.3
F=4.8×10^-5N
Answer:
t_total = 6.99 s
Explanation:
It asks us how long it takes to hear the sound, for this we must look for the time (t₁) it takes for the sound to reach the microphone, the time it takes for the video signal (t₂) to reach the television and the time (₃) it takes for the TV sound to reach us, so the total delay time is
t_total = t₁ + t₂ + t₂
we look for t1, it indicates that the distance x = 22m
v = x / t
t = x / v
t₁ = 22/343
t₁ = 6.41 10-2 s
time t₂
t₂ = 4500 103/3 108
t₂ = 1.5 10-5 s
time t₃
t₃ = 2/343
t₃ = 5.83 10⁻³
Total time is
t_total = t₁ + t₂ + t₃
t_total = 6.41 10⁻² + 1.5 10⁻⁵ + 0.583 10⁻²
t_total = 6.99 s
Answer: The trip takes 
Explanation:
Velocity 
is the variation of the position of a body (distance traveled 
) with time 
:
In this case, the car travels a distance 
at a velocity 
and we need to find the time it takes the trip.
Isolating :
Finally:
