Answer:
t = 2 s
Explanation:
In order to find the time taken by the stone to fall from the top of the building to the ground we can use 2nd equation of motion. 2nd equation of motion is as follows:
s = Vit + (0.5)gt²
where,
t = time = ?
Vi = Initial Velocity = 20 m/s
s = height of building = 60 m
g = 9.8 m/s²
Therefore,
60 m = (20 m/s)t + (0.5)(9.8 m/s²)t²
4.9t² + 20t - 60 = 0
solving this quadratic equation we get:
t = -6.1 s (OR) t = 2 s
Since, the time cannot be negative in magnitude.
Therefore,
<u>t = 2 s</u>
Answer:
Extension is 12.14m
Explanation:
mass of ornament=42g,weight of ornament=mg=42*9.8=411.6
Force constant(k)= 33.9N/m
F=ke
e=F/k
F is force, e is extension
F=weight of ornament
e=411.6/33.9
e=12.14m
Answer:
It means that the star is moving towards us.
Explanation:
The star is moving toward us; shift to a shorter wavelength. A shorter wavelength means a shift to the blue end of the spectrum (a blueshift) so that the object is moving toward us.
Answer:
1.c,2.c,3.a,4.d
Explanation:
the following answer are listed with there number
