Answer: The first one
Explanation: I think it's the first one because it says what is the "least" gravitational potential energy story between the prairie dog and Earth that said resting in its borrow is using less energy
Answer:
The net friction force is 8.01 N
Explanation:
Net friction force = mass of hockey puck × acceleration
From the equations of motion
v^2 = u^2 + 2as
v = 40 m/s
u = 0 m/s (puck was initially at rest)
s = 30 m
40^2 = 0^2 + 2×a×30
60a = 1600
a = 1600/60 = 26.7 m/s^2
The acceleration of the puck is 26.7 m/s^2
Net friction force = 0.3 × 26.7 = 8.01 N
Answer:
The answer to your question is: 13.2 m/s
Explanation:
final speed (fs) = 77 m/s
t = 6.5 s
gravity (g) = 9.81 m/s2
initial speed (is) = ?
Formula
fs = is + gt from this equation we clear "is" = fs - gt
Substitution is = 77 - (9,81)(6.5)
Process is = 77 - 63.8
is = 13.2 m/s
Explanation:
It is given that,
Mass of the soccer ball, m = 0.425 kg
Speed of the ball, u = 15 m/s
Angle with horizontal, 
Time for which the player's foot is in contact with it, 
Part A,
The x component of the soccer ball's change in momentum is given by :



The y component of the soccer ball's change in momentum is given by :



Hence, this is the required solution.
Explanation:
(a)
Critical angle is the angle at the angle of refraction is 90°. After the critical angle, no refraction takes place.
Using Snell's law as:
Where,
is the angle of incidence
is the angle of refraction = 90°
is the refractive index of the refraction medium
is the refractive index of the incidence medium
Thus,
The formula for the calculation of critical angle is:
Where,
is the critical angle
(b)
No it cannot occur. It only occur when the light ray bends away from the normal which means that when it travels from denser to rarer medium.