Answer:
Speed, u = 29.4 m/s
Explanation:
Given that, A ball thrown straight up climbs for 3.0 sec before falling, t = 3 s
Let u is speed with which the ball is thrown up. When the ball falls, v = 0
Using first equation of motion as :
v = u + at
Here, a = -g
So, u = g × t
u = 29.4 m/s
So, the speed with which the ball was thrown is 29.4 m/s. Hence, this is the required solution.
Answer:
f=896Hz
Explanation:
Given data
Vs(speed of the ambulance)={(104 km/h)*(1000m*(1 h/3600)}=28.9m/s
f(frequency of the ambulance siren)=821 Hz
v(speed of sound)=345 m/s
Vo(speed of the observer)=0 m/s
To find
f(The ambulance is approaching the person)
Solution
From Doppler effect
As the ambulance approaches the we assign a positive sign for speed "vs" of the ambulance
So
Substitute the values from given data
Answer:
3.39724 seconds
23.0824792352 m, 101.917520765 m
13.58896 m/s
Explanation:
t = Time taken
u = Initial velocity
v = Final velocity
s = Displacement
a = Acceleration
The equation of motion will be
The time at which the cars collide is 3.39724 seconds
Car B traveled 23.0824792352 m and Car A traveled 125-23.0824792352 = 101.917520765 m
The speed of car B is 13.58896 m/s