Answer:
v_average =0
Explanation:
In kinematics the average speed defined with the distance interval traveled in a given time interval
V = Δx /Δt
in this case the tennis ball travels a distance h to the highest point and a distance h from the highest point to the floor, so the distance you travel zero
Dy = h -h = 0
therefore the average speed should be zero
v_average =0
Answer:
The approximate combined sound intensity is
Explanation:
The decibel scale intensity for busy traffic is 80 dB. so intensity will be
, therefore
In the same way for the loud conversation having a decibel intensity of 70 dB.
, therefore
Finally we add both of them , is the approximate combined sound intensity.
Answer:
person must have to use the concave lens of focal length 3.5 m
Explanation:
If the person can see upto distance of 3.5 m from eye
then in order to see the object at large distance we need to use
so by lens formula we have
so we have
f = -3.5 m
so person must have to use the concave lens of focal length 3.5 m
Answer:
Alternating current
Explanation:
The electrical current periodically changes direction.
Answer:
Explanation:
Reaction force of inclined surface
R = mgcos30
=60 x 9.8 x .866
= 509 N
Force of kinetic friction
= .12 x 509
= 61.08 N
b )
net force downwards = mgsinθ - μmgcosθ
acceleration = g sinθ - μgcosθ
9.8 sin30 - .12 x 9.8 x cos30
= 4.9 - 1.018
a= 3.88 m /s²
c )
v² = 2as
= 2 x 3.88 x 20
v = 12.46 m /s