Answer:
The time taken is missing in the question. The time is 18 minutes.
The answer is 34.3 km/hr
Explanation:
Average velocity is the speed or the velocity which is required to cover a distance in a time interval.
The time taken is = 18 min
= 18/60 hours
The distance from the university to her home is = 10.3 km
Therefore, the average velocity is = displacement/time taken
= 10.3 / (18/60) km/hr
= 34.3 km/hr
Hence, the average velocity is 34.3 km/hr
Answer:
Explanation:
Wave length of sound from each of the speakers = 340 / 1700 = .2 m = 20 cm
Distance between first speaker and the given point = 4 m.
Distance between second speaker and the given sound
= √ 4² + 2² = √16 +4 = √20 = 4.472 m
Path difference = 4.472 - 4 = .4722 m.
Path difference / wave length = 0.4772 / 0.2 = 2.386
This is a fractional integer which is neither an odd nor an even multiple of half wavelength. Hence this point of neither a perfect constructive nor a perfect destructive interference.
Answer:
time required after impact for a puck is 2.18 seconds
Explanation:
given data
mass = 30 g = 0.03 kg
diameter = 100 mm = 0.1 m
thick = 0.1 mm = 1 ×
m
dynamic viscosity = 1.75 ×
Ns/m²
air temperature = 15°C
to find out
time required after impact for a puck to lose 10%
solution
we know velocity varies here 0 to v
we consider here initial velocity = v
so final velocity = 0.9v
so change in velocity is du = v
and clearance dy = h
and shear stress acting on surface is here express as
= µ 
so
= µ
............1
put here value
= 1.75×
× 
= 0.175 v
and
area between air and puck is given by
Area =
area =
area = 7.85 ×
m²
so
force on puck is express as
Force = × area
force = 0.175 v × 7.85 × 
force = 1.374 ×
v
and now apply newton second law
force = mass × acceleration
- force = 
- 1.374 ×
v = 
t = 
time = 2.18
so time required after impact for a puck is 2.18 seconds
Answer:
Wet surfaces areaA=+25.3ft^2
Explanation:
Using F= K×A× S^2
Where F= drag force
A= surface area
S= speed
Given : F=996N S=20mph A= 83ft^2
K = F/AS^2=996/(83×20^2)
K= 996/33200 = 0.03
1215= (0.03)× A × 18^2
1215=9.7A
A=1215/9.7=125.3ft^2
Answer:
r= 2.17 m
Explanation:
Conceptual Analysis:
The electric field at a distance r from a charge line of infinite length and constant charge per unit length is calculated as follows:
E= 2k*(λ/r) Formula (1)
Where:
E: electric field .( N/C)
k: Coulomb electric constant. (N*m²/C²)
λ: linear charge density. (C/m)
r : distance from the charge line to the surface where E calculates (m)
Known data
E= 2.9 N/C
λ = 3.5*10⁻¹⁰ C/m
k= 8.99 *10⁹ N*m²/C²
Problem development
We replace data in the formula (1):
E= 2*k*(λ/r)
2.9= 2*8.99 *10⁹*(3.5*10⁻¹⁰/r)
r =( 2*8.99 *10⁹*3.5*10⁻¹⁰) / (2.9)
r= 2.17 m