Answer:
e) about 10 m/s
Explanation:
Acceleration due to gravity is nominally* 9.8 m/s². That means the change in velocity each second is ...
(9.8 m/s²)(1 s) = 9.8 m/s ≈ 10 m/s
_____
* This is the value expected to be used in the solution of many math and physics problems. The standard value of 'g' on Earth is defined as 9.80665 m/s². It varies from place to place and with altitude. At any given place, it may also vary with time as a result of changes in mass distribution within the Earth.
I think its b because more wave crests pass each second when frequency increases meaning the wavelength shortens?
The centripetal force is calculated using the following rule:
F = (m * v^2) / r where
F is the centripetal force = 6000 newtons
m is the mass of the object = 1200 kg
v is the uniform velocity of the object = 20 m/sec
r is the radius of the circular curve that we want to calculate
Substitute with these givens in the above equation to get the radius as follows:
6000 = (1200 * (20)^2) / r
6000 = 480000 r
r = 80 meters
All credit goes to the person who answered this years ago:)
Reaches max height at t = 2.42s.
Explanation:
I've assumed we are neglecting air resistance. If not let me know and I'll update.
We want to examine the behaviour of the ball in the y-direction. In the absence of air resistance the only force acting on the ball is gravity, which produces an acceleration in the negative y direction. From Newton's 2nd law:
m
d
2
y
d
t
2
=
−
m
g
m
d
2
y
d
t
2
=
−
m
g
Integrating:
d
y
d
t
=
−
∫
g
d
t
d
y
d
t
=
−
g
⋅
t
+
C
From initial conditions,
d
y
d
t
=
v
y
(
t
)
,
v
0
=
v
(
0
)
=
31
⋅
sin
(
50
)
∴
v
y
(
t
)
=
v
0
−
g
⋅
t
The maximum height will be reached at
v
y
=
0
so we solve for t.
v
y
(
t
h
max
)
=
0
⇒
v
0
=
g
⋅
t
h
max
t
h
max
=
v
0
g
=
31
⋅
sin
(
50
)