T = tension force in the rope in upward direction
m = mass of the box attached at end of rope = 56 kg
W = weight of the box in downward direction due to gravity
a = acceleration of the box in upward direction = 5.10 m/s²
weight of the box is given as
W = mg
inserting the values
W = (56) (9.8)
W = 548.8 N
force equation for the motion of the box is given as
T - W = ma
inserting the values
T - 548.8 = (56) (5.10)
T = 834.4 N
Answer:
(D) None
Explanation:
The force of gravity is the force pulling every element of matter together. The more the matter the higher the force of gravity.
Examples of this force at work are;
- The force that causes an apple to fall from the tree
- The force that causes a rock to roll downside a hill
- The force causing people to walk on the earth surface instead of floating
The force that facilitates a pen on your hand to write on a paper is friction force between the pen and the paper. Gravitational force acts downwards thus force applied on an object beside you is not the force of gravity.
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
Answer:
Acceleration will be 
Explanation:
We have given initial speed of the car is 70 km/hr
We know that 1 km = 1000 m
And 1 hour = 3600 sec
So 
It is given that car stops in 12 sec
So final speed of the car v = 0 m/sec
Time t = 12 sec
From first equation of motion v = u+at
So 
( negative sign indicates that speed of the car will constantly decrease )
Answer:
2.083 V.
Explanation:
Stopping potential is the potential that is required to stop the current to zero . This potential is applied externally to oppose the potential created by the photoelectric effect . It gives the measure the photoelectric potential being generated .
Here current drops to 25 μA to 19 μA by a potential of 500mV
Change in current
= 25 - 19 = 6 μA
Voltage requirement for unit reduction in current
= 500 / 6 μA
To reduce current 0f 25 μA
requirement of V = (500 / 6 ) x 25 = 2083.33 mV = 2.083 V.