Answer:
2.5 s, 5 m
Explanation:
The equations for the horizontal and vertical position of Lukalu are:
we can find the time it takes her to reach the ground by requiring that the vertical position becomes zero:
y(t) = 0
So we find:
The horizontal distance of Lukalu instead will be given by the equation for the horizontal position, substituting t = 2.5 s:
Answer:
P = 5880 J
Explanation:
Given that,
The mass of the block, m = 30 kg
The block is sitting at a height of 20 m.
The block will have gravitational potential energy. The formula for gravitational potential energy is given by :
So, the required potential energy is equal to 5880 J.
Answer:
Given that
The earth spins on its axis once a day and orbits the sun once a year (365 1/4 days)
a)
When earth spins on its axis
We know that earth take 1 day to complete one revolution around its own axis.
T= 1 day = 24 hr = 24 x 3600 s
T=86400 s
We know that
T=2π/ω
ω= 2π/T
ω= 2π/86400
ω=7.27 x 10⁻5 rad/s
b)
When earth revolve around earth
T =365 1/4 days = 365.25 days
T= 365.24 x 86400 s
T=31557600
We know that
T=2π/ω
ω= 2π/T
ω= 2π/31557600
ω=1.99 x 10⁻⁷ rad/s
-- Accelerating at the rate of 8 m/s², Andy's speed
after 30 seconds is
(8 m/s²) x (30.0 s) = 240 m/s .
-- His average speed during that time is
(1/2) (0 + 240 m/s) = 120 m/s .
-- In 30 sec at an average speed of 120 m/s,
Andy will travel a distance of
(120 m/s) x (30 sec) = 3,600 m
= 3.6 km .
"But how ? ! ?", you ask.
How in the world can Andy leave a stop light and then
cover 3.6 km = 2.24 miles in the next 30 seconds ?
The answer is: His acceleration of 8 m/s², or about 0.82 G
is what does it for him.
At that rate of acceleration ...
-- Andy achieves "Zero to 60 mph" in 3.35 seconds,
and then he keeps accelerating.
-- He hits 100 mph in 5.59 seconds after jumping the light ...
and then he keeps accelerating.
-- He hits 200 mph in 11.2 seconds after jumping the light ...
and then he keeps accelerating.
-- After accelerating at 8 m/s² for 30 seconds, Andy and his
car are moving at 537 miles per hour !
We really don't know whether he keeps accelerating,
but we kind of doubt it.
A couple of observations in conclusion:
-- We can't actually calculate his displacement with the information given.
Displacement is the distance and direction between the starting- and
ending-points, and we're not told whether Andy maintains a straight line
during this tense period, or is all over the road, adding great distance
but not a lot of displacement.
-- It's also likely that sometime during this performance, he is pulled
over to the side by an alert cop in a traffic-control helicopter, and
never actually succeeds in accomplishing the given description.
