Answer:
17 m/s south
Explanation:
= Mass of dog = 10 kg
= Mass of skateboard = 2 kg
v = Combined velocity = 2 m/s
= Velocity of dog = 1 m/s
= Velocity of skateboard
In this system the linear momentum is conserved
The velocity of the skateboard will be 17 m/s south as the north is taken as positive
Answer: The correct answer is "Instrument A is placed closer to Sam than instrument B".
Explanation:
The sound can be soft or loud. Loudness depends on the amplitude of the sound wave. Higher the amplitude, more will be loudness. Lower the amplitude, lesser will be loudness.
Pitch depends on the frequency.
In the given problem, the instruments A and B generate sound waves of the same amplitude and at the same time.
Loudness depends on the sound energy produced as the energy of the sound is directly proportional to the square of the amplitude. It also depends on the distance between the source and the receiver.
Sam records a louder sound from instrument A than from instrument B. It means that there is mismatch in loudness. It can happen due to the placement of the instrument A closer to Sam than instrument B.
Therefore, the correct option is "Instrument A is placed closer to Sam than instrument B".
Answer:
-3413 ft/s2
Explanation:
We need to know the velocity with which he landed on the snow.
He 'dropped' from 512 feet. This is the displacement. His initial velocity is 0 and the acceleration of gravity is 32 ft/s2.
We use the equation of mition
v and u are the initial and final velocities, a is the acceleration and s is the displacement. Putting the appropriate values
This is the final velocity of the fall and becomes the initial velocity as he goes into the snow.
In this second motion, his final velocity is 0 because he stops after a displacement of 4.8 ft. We use the same equation of motion but with different values. This time, 
, v = 0 and s = 4.8 ft.
Note that this is negative because it was a deceleration, that is, his velocity was decreasing.
Answer:
30 (kg)
Explanation:
therefore the mass of the ball is 2 so 30 (kg)
Answer:
407 steps
Explanation:
From the question,
P = mgh/t........... Equation 1
Where P = power, m = mass, g = acceleration due to gravity, h = height, t = time.
Make h the subject of the equation
h = Pt/mg............. Equation 2
Given: P = 746 W, t = 1 minute = 60 seconds, m = 70 kg.
Constant: g = 9.8 m/s²
Substitute into equation 2
h = 746(60)/(70×9.8)
h = 44760/686
h = 65.25 m
h = 6525 cm
number of steps = 6525/16
number of steps = 407 steps
