Speed of sound in cold air < Speed of sound in Warm air < Speed of sound in hot molten lead < Speed of sound in water
Explanation:
Step 1:
Speed of sound in water varies from 1450 to 1498 meters per second
Speed of sound in Hot Molten lead is approximately 1210 meters per second
Speed of sound in warm air is approximately 338.89 meters per second
Speed of sound in cold air is approximately 293.33 meters per second
Step 2:
In warm air sound travels faster than that of sound travelling nature in cold air.
∴ Speed of sound in cold air < Speed of sound in Warm air < Speed of sound in hot molten lead < Speed of sound in water
Speed of sound in cold air the slowest while Speed of sound in water is the fastest mean.
Answer:
acceleration 8 km/h/s south
Explanation:
First of all, let's remind that a vector quantity is a quantity which has both a magnitude and a direction.
Based on this definition, we can already rule out the following two choices:
distance: 40 km
speed: 40 km/h
Since they only have magnitude, they are not vectors.
Then, the following option:
velocity: 5 km/h north
is wrong, because the car is moving south, not north.
So, the correct choice is
acceleration 8 km/h/s south
In fact, the acceleration can be calculated as
where
v = 40 km/h is the final velocity
u = 0 is the initial velocity
t = 5 s is the time
Substituting,
And since the sign is positive, the direction is the same as the velocity (south).
When the velocity of an object changes, it is acted upon by a force
Answer:
The statement is true.
Both gravity and centrifugal force act on the Moon which causes it get pulled towards Earth (gravity) and get "flung away" so it doesn't hit us (centrifugal force).
