Answer:
Explanation:
We know that
Δr = r₁ - r₀
r₀ = 0 i + 0 j
r₁ = (162+137*Cos(31º)+137*Cos(-48º)) i + (0+137*Sin(31º)+137*Sin(-48º)) j = (371.1028 i - 31.2506 j) ft
Δr = r₁ - r₀ = (371.1028 i - 31.2506 j) - (0 i + 0 j) = (371.1028 i - 31.2506 j) ft
Magnitude:
Δr = √((371.1028)²+(-31.2506)²) = 372.4163 ft
Angle:
tan θ = (- 31.2506 / 371.1028) = -0.0839 ⇒ θ = tan⁻¹(-0.0839) = - 4.8135º
(below the horizontal).
Answer:
3.35 seconds
Explanation:
Use one of the equations of accelerated motion:
Δd = v1Δt+1/2aΔt^2
and rearrange for Δt which is time
Δt = √(2Δd)/a
now we can substitute in the values
a= 9.8 (acceleration due to gravity) and Δd= 55 as that is the height of the building
Δt = √(2*55)/9.8
Δt = 3.3503s
Answer:
Approximately 
upwards (assuming that 
.)
Explanation:
External forces on this astronaut:
- Weight (gravitational attraction) from the earth (downwards,) and
- Normal force from the floor (upwards.)
Let 
denote the magnitude of the normal force on this astronaut from the floor. Since the direction of the normal force is opposite to the direction of the gravitational attraction, the magnitude of the net force on this astronaut would be:
.
Let 
denote the mass of this astronaut. The magnitude of the gravitational attraction on this astronaut would be 
.
Let 
denote the acceleration of this astronaut. The magnitude of the net force on this astronaut would be 
.
Rearrange to obtain an expression for the magnitude of the normal force on this astronaut:
.
The question for this problem would be the minimum headphone delay, in ms, that will cancel this noise.
The 200 Hz. period = (1/200) = 0.005 sec. It will need to be delayed by 1/2, so 0.005/2, that is = 0.0025 sec. So converting sec to ms, will give us the delay of:Delay = 2.5 ms.
Answer:
FALSE
Explanation:
Velocity = speed with direction.
Think of speed and direction like rockets and missiles. Rockets are not smart. Missiles are smart. Rockets go in one direction. Missiles can track their targets, they have a specific destination, a specific direction.
Velocity is often used in physics, because its almost useless to know how fast an object is going if you don't know which direction it is going.
Think of it like this. If the Weather man told you a hurricane was traveling at 30 miles an hour, but didn't tell you which direction it was going, you would have no idea where to run, or if it was going to hit you at all. However, if he told you it was going 30 miles an hour to the North, and you were West of it, you would be fine, and wouldn't have to worry.
