Answer:
129.74 Hz
Explanation:
Given:
Wave velocity ( v ) = 346 m / sec
wavelength ( λ ) = 2.69 m
We have to calculate Frequency ( f ) :
We know:
v = λ / t [ f = 1 / t ]
v = λ f
= > f = v / λ
Putting values here we get:
= > f = 346 / 2.69 Hz
= > f = 34600 / 269 Hz
= > f = 129.74 Hz
Hence, frequency of sound is 129.74 Hz.
Answer:
a) 17 km
b) 9 km
Explanation:
The distance is the length of the path.
A to C: 5 km
B to C: 4 km
C to B: 4 km
B to C: 4 km
Total distance = 5 km + 4 km + 4 km + 4 km = 17 km
Displacement is the difference between the starting point and ending point.
Displacement = 9 km − 0 km = 9 km
Brain-powered cars?
The answer would be people who lack motor skills in their legs.
Answer:
1.36m/s
Explanation:
We are given that
Mass of one acrobat,
Mass of another acrobat,


We have to find their velocity immediately after they grab onto each other.
The collision between two acrobat is inelastic
According to law of conservation of momentum

Substitute the values



Answer:
(a) 2.542 cm
(b) 272.7°C
Explanation:
diameter, d = 2.540 cm
T1 = 20°C
α = 11 x 10^-6 /°C
(a) Let d' be the diameter.
T2 = 87°C
Use he formula for the areal expansion
A' = A ( 1 + βΔT)
where, β is the coefficient of areal expansion and ΔT is teh rise in temperature, A' be the area at high temperature and A be the area at low temperature.
β = 2 α = 2 x 11 x 106-6 = 22 x 10^-6 /°C
So,

D'^2 = 2.54^2 ( 1 + 22 x 10^-6 x 67)
D' = 2.542 cm
(b) Let the change in temperature is ΔT.
Use the formula for the volumetric expansion
ΔV = V x γ x ΔT
Where, γ = 3 x α = 3 x 11 x 10^-6 = 33 x 10^-6 /°C
0.9/100 = 33 x 10^-6 x ΔT
ΔT = 272.7°C