Answer:
The light wave could be reflected by the object
He has a mass of 56 kg.
The equation given is PE = mgh.
PE = 4620 J
h = 8.4
g = 9.8
Therefore:
4620 = 82.32m
m = 4620/82.32
m = 56 (rounded to two significant digits)
Answer:
118 N
Explanation:
Given mass of the block, m = 4.00kg.
The acceleration of the elevator, a = 3.0 m/s^2.
As elevotar attaced with spring scale and accelerating upward
(block and elevator), so total force

Here, mg is the weight of the block downward direction.
or

substitute the given value, we get

= 117.6 N = 118 N.
Thus, the reading on the spring scale to 3 significant figures is 118 N.
Answer:
0.707m
Explanation:
from formula of range i.e R=Usin2Q/g