Answer:
300 m/s
Explanation:
The difference in time between the two bangs is 1 s.
Thus;
t2 - t1 = 1
We know that distance/time = speed.
Thus;
d2/v - d1/v = 1
Multiply through by v to get;
d2 - d1 = v
Where v is speed of sound in air.
d1 = 350 m
d2 = (150 × 2) + 350 = 650 m
Thus;
v = d2 - d1 = 650 - 350 = 300 m/s
Answer:
18.89cm
Explanation:
As we know that the person is standing 5m in front of the camera

The focal length of the lens =50cm
f=50 cm
By Lens formula we have:

By the formula of magnification

The height of the image formed is 18.89cm.
Answer:
puck decelerates due to the kinetic frictional force μk mg
Explanation:
given data
total distance = 12 m
coefficient of kinetic friction = 0.28
solution
we will apply equation of motion that is
v² - u² = 2 × a × s ................1
we know acceleration will be
a =
Then we have
Force = mass × acceleration .................2
m ×
= -μk mg
The puck decelerates due to the kinetic frictional force μk mg
and frictional force is negative as it opposes the motion.
so we get initial velocity of the puck which is strike.