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:
Explanation:
average speed is distance traveled over time
v = (50 + 30(1.5)) / (2 + 1.5) = 27.1428571...
v = 27 km/hr
Properties of electromagnetic radiation and photons. ... we find the types of energy that are lower in frequency ( and thus longer in wavelength) than visible light. Seeee
They are attractive
They don’t depend on charge
