The force needed to accelerate an elevator upward at a rate of 
is 2000 N or 2 kN.
<u>Explanation:
</u>
As per Newton's second law of motion, an object's acceleration is directly proportional to the external unbalanced force acting on it and inversely proportional to the mass of the object.
As the object given here is an elevator with mass 1000 kg and the acceleration is given as , the force needed to accelerate it can be obtained by taking the product of mass and acceleration.
So 2000 N or 2 kN amount of force is needed to accelerate the elevator upward at a rate of .
The energy carried by a single photon of frequency f is given by:
where
is the Planck constant. In our problem, the frequency of the photon is
, and by using these numbers we can find the energy of the photon:
I think the answer is ruthorford
Answer:
60.025m.
Explanation:
S= ut + at^2/2 (2nd equation of motion)
S= 0 + (9.8)(3.5)^2 /2 (free fall case, initial velocity = 0)
S = 4.9 x 12.25
S= 60.025 m.
Disclaimer: did math in my head, so you better double check with a calculator.
Answer:
the person will be in the shore at 10.73 minutes after launch the shoe.
Explanation:
For this we will use the law of the lineal momentum.
Also,
L = MV
where M is de mass and V the velocity.
replacing,
wher Mi y Vi are the initial mass and velocity, Mfp y Vfp are the final mass and velocity of the person and Mfz y Vfz are the final mass and velocity of the shoe.
so, we will take the direction where be launched the shoe as negative. then:
(70)(0) = (70-0.175)(
) + (0.175)(-3.2m/s)
solving for ,
= 
= 0.008m/s
for know when the person will be in the shore we will use the rule of three as:
1 second -------------- 0.008m
t seconds-------------- 5.15m
solving for t,
t = 5.15m/0.008m
t = 643.75 seconds = 10.73 minutes
