Answer:
59.51 mph.
Explanation:
The following data were obtained from the question:
Distance (d) = 147 miles
Time (t) = 2.47 hours.
Speed (S) =?
Speed is defined as the distance travelled per unit time. Mathematically, it is expressed as:
Speed (S) = Distance (d) / time (t)
S = d/t
With the above formula, we can obtain the speed of the girl as illustrated below:
Distance (d) = 147 miles
Time (t) = 2.47 hours.
Speed (S) =?
S = d/t
S = 147 miles / 2.47 hours.
S = 59.51 miles per hour (mph)
Thus, the speed of the girl is 59.51 mph.
Answer: The correct answer is "the pitch drops to a lower pitch once the ambulance passes by Juan".
Explanation:
Doppler effect is the phenomenon in which there is an increase or decrease in the frequency when there is relative motion between the source and listener.
Pitch depends on the frequency. if the frequency increases then pitch increases.
When the source and the listener are moving towards each other then there is increase in the frequency. When the source and the listener are moving away each other then there is decrease in the frequency.
In the given problem, Juan is standing on the street. An ambulance moves toward him and then passes by the pitch drops to a lower pitch once the ambulance passes by Juan.
Answer:
Explanation:
Speed= distance/time
Or time = distance/speed
According to your question
Speed=15m/s
and. Distance=1.2km. ,we must change kilometer in meter because given speed is in m/s
D= 1.2km = 1.2×1000m =1200meter
Time = distance/ speed
1200/15 =80second
Or. 1min and 20 sec will be your answer.
Answer:
The velocity of the astronaut is, v = - 0.36 m/s
Explanation:
Given data,
The mass of the astronaut, M = 84 kg
The mass of the gas expelled by the thruster, m = 35 g
= 0.035 g
The velocity of the gas expelled, v = 875 m/s
According to the conservation of momentum,
MV + mv = 0
V = - mv / M
Substituting the values,
V = - 0.035 x 875 / 84
= - 0.36 m/s
The negative sign in the velocity indicates the astronaut moves opposite to the direction of velocity of gas.
Hence, the velocity of the astronaut is, v = - 0.36 m/s
