A constant velocity implies the two forces must be equal and opposite.
Friction acts horizontal to the ground, therefore we must find the force applied to the sled rope that acts horizontal to the ground.
Do this by resolving:
Force = 80cos53
The force opposing this is equal, and so also = 80cos53 = 48 N (2 sig. fig.)
Your grade will probably go down to a D 68% or little higher than that
The speed of a proton after it accelerates from rest through a potential difference of 350 V is
.
Initial velocity of the proton 
Given potential difference 
let's assume that the speed of the proton is
,
Since the proton is accelerating through a potential difference, proton's potential energy will change with time. The potential energy of a particle of charge
when accelerated with a potential difference
is,

Due to Work-Energy Theorem and Conservation of Energy - <em>If there is no non-conservative force acting on a particle then loss in Potential energy P.E must be equal to gain in Kinetic Energy K.E</em> i.e

If the initial and final velocity of the proton is
and
respectively then,
change in Kinetic Energy 
change in Potential Energy 
from conservation of energy,

so, 

To read more about the conservation of energy, please go to brainly.com/question/14668053
The energy absorbed by photon is 1.24 eV.
This is the perfect answer.
Answer: 6067.5 N
Explanation:
Work = Change in Energy. To start, all of the energy is kinetic energy, so find the total KE using: KE = 1/2(m)(v^2). Plug in 1980 kg for m and 15.5 m/s for v and get KE = 237847.5 J.
Now, plug this in for work: Work = Force * Distance; so, divide work by distance to get 6067.5 N.