Answer:0.302
Explanation:
Given
mass of crate m=27 kg
Force required to set crate in motion is 80 N
Once the crate is set in motion 56 N is require to move it with constant velocity
i.e. 80 N is the amount of force needed to just overcome static friction and 56 is the kinetic friction force
thus

where
is the coefficient of static friction and N is Normal reaction





Answer:
Question 1 the anwser is 300 meters. Question 2 the answer is speed.
is Explanation:
Hi There,
This is False.
Hope this helped!
Answer:
the longest wavelength of incident sunlight that can eject an electron from the platinum is 233 nm
Explanation:
Given data
Φ = 5.32 eV
to find out
the longest wavelength
solution
we know that
hf = k(maximum) +Ф ...............1
here we consider k(maximum ) will be zero because photon wavelength max when low photon energy
so hf = 0
and hc/ λ = +Ф
so λ = hc/Ф ................2
now put value hc = 1240 ev nm and Φ = 5.32 eV
so hc = 1240 / 5.32
hc = 233 nm
the longest wavelength of incident sunlight that can eject an electron from the platinum is 233 nm
Answer:
2.47 m
Explanation:
Let's calculate first the time it takes for the ball to cover the horizontal distance that separates the starting point from the crossbar of d = 52 m.
The horizontal velocity of the ball is constant:

and the time taken to cover the horizontal distance d is

So this is the time the ball takes to reach the horizontal position of the crossbar.
The vertical position of the ball at time t is given by

where
is the initial vertical velocity
g = 9.8 m/s^2 is the acceleration of gravity
And substituting t = 2.56 s, we find the vertical position of the ball when it is above the crossbar:

The height of the crossbar is h = 3.05 m, so the ball passes

above the crossbar.