Answer:
The slower runner is 1.71 km from the finish line when the fastest runner finishes the race.
Explanation:
Given;
the speed of the slower runner, u₁ = 11.8 km/hr
the speed of the fastest runner, u₂ = 15 km/hr
distance, d = 8 km
The time when the fastest runner finishes the race is given by;
The distance covered by the slower runner at this time is given by;
d₁ = u₁ x 0.533 hr
d₁ = 11.8 km/hr x 0.533 hr
d₁ = 6.29 km
Additional distance (x) the slower runner need to finish is given by;
6.29 km + x = 8km
x = 8 k m - 6.29 km
x = 1.71 km
Therefore, the slower runner is 1.71 km from the finish line when the fastest runner finishes the race.
The correct answer to the question is: Sound wave.
EXPLANATION:
Before going to answer this question, first we have to understand longitudinal wave.
A longitudinal wave is a mechanical wave in which the direction of propagation of wave is parallel to the direction of particle vibration.
This wave propagates through a medium in the form of compression and rarefaction.
Compression are the regions of high pressure zones where the particles of the medium are closely aggregated to each other.
Rarefaction is the region of low pressure where particles of the medium are not so close to each other as compared to compression.
The longitudinal wave can not propagate in space. It always needs a medium for it's propagation. The medium may be solid, liquid or gas .
For instance, sound wave is a longitudinal wave.
Hence, the correct answer of this question is sound wave which needs a medium for it's propagation.
Answer:
Tangential speed = 5.72 m/s
Centripetal acceleration = 
Explanation:
The tangential speed, V, is given by
where 
is the angular speed and is given by 
(f is the angular frequency or frequency of rotation)
Thus,
The centripetal acceleration,a, is given by
Answer:
the magnitude of the displacement after 5s is 137.31 m.
Explanation:
Given;
initial velocity of the projectile, u = 60 m/s
angle of projection, θ = 60°
time of motion, t = 5s
the vertical component of the velocity, 
The magnitude of the displacement after 5s is calculated as;
Therefore, the magnitude of the displacement after 5s is 137.31 m.
all except the rubber boots.
