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: The height of its fourth bounce = 0.43m
Explanation:
The coefficient of restitution denoted by (e), is the ratio that shows the final velocity to initial relative velocity between two objects after collision
IT is given by the formula in terms of height as
Coefficient of Restitution, e = √(2gh))/√(2gH) = √(h/H)
Where
Coefficient of Restitution, e= 0.821
H = 2.07 m
At fourth bounce , we have that
Coefficient of Restitution, e⁴ =√(h₄/H)
Putting the given values and solving , we have,
e⁴ =√(h₄/H)
= 0.821⁴ = √(h₄/2.07)
(0.821⁴ )² =h₄/2.07
0.2064 x 2.07 = 0.427 = 0.43
At fourth bounce, h₄ height = 0.43m
Answer:
Explanation:
Capacitance of capacitor
= ε₀ A / d , ε₀ is permittivity of space , A is area of plate , d is distance between plates.
= 8.85 x 10⁻¹² x 2 x 10⁻³ / (6 x 10⁻³)
= 2.95 x 10⁻¹² F
Electric field E = V / d , V is potential difference
V = E x d
= 100 x 10³ x 6 x 10⁻³
= 600 V
Charge on the capacitor
= capacitance x potential difference
= 2.95 x 10⁻¹² x 600
= 17.7 x 10¹⁰ C
Answer:
Δt = 5.85 s
Explanation:
For this exercise let's use Faraday's Law
emf = 
- d fi / dt
= B. A
\phi = B A cos θ
The bold are vectors. It indicates that the area of the body is A = 0.046 m², the magnetic field B = 1.4 T, also iindicate that the normal to the area is parallel to the field, therefore the angle θ = 0 and cos 0 =1.
suppose a linear change of the magnetic field
emf = - A 
Dt = - A 
the final field before a fault is zero
let's calculate
Δt = - 0.046 (0- 1.4) / 0.011
Δt = 5.85 s
Answer:
Linear and rotational Kinetic Energy + Gravitational potential energy
Explanation:
The ball rolls off a tall roof and starts falling.
Let us first consider the potential energy or more specifically gravitational potential energy (
; 
= mass of the ball, 
= acceleration due to gravity, 
= height of the roof). This energy comes because someone or something had to do work to take the ball to the top of the roof against the force of gravity. The potential energy is naturally maximum at the top and minimum when the ball finally reaches the ground.
Now, the ball starts to roll and falls off the roof. It shall continue rotating because of inertia (Newton's first law). This contributes to the rotational kinetic energy (
; 
=moment of inertia of the ball & 
= angular velocity).
Finally comes the linear kinetic energy or simply, kinetic energy (
) which is caused due to the velocity 
of the ball.
