2/5 = .4
.4*100= 40%
Alex spends more time
Answer:
1977.696 J
Explanation:
Given;
Weight of the box = 28.0 kg
Force applied by the boy = 230 N
angle between the horizontal and the force = 35°
Therefore,
the horizontal component of the force = 230 × cosθ
= 230 × cos 35°
= 188.405 N
Coefficient of kinetic friction, μ = 0.24
Force by friction, f = μN
here,
N = Normal force = Mass × acceleration due to gravity
or
N = 28 × 9.81 = 274.68 N
therefore,
f = 0.24 × 274.68
or
f = 65.9232 N
Now,
work done by the boy, W₁ = 188.405 N × Displacement
= 188.405 N × 30
= 5652.15 J
and,
the
work done by the friction, W₂ = - 65.9232 N × Displacement
= - 65.9232 N × 30 m
= - 1977.696 J
[ since the friction force acts opposite to the direction of motion, therefore the workdone will be negative]
Given required solution
M=10kg W=? W=Fd
v=5.0m/s F=mg
t=2.40s =10*10=100N
S=VT
=5m/s*2.4s
=12m
so W=12*100
W=1200J
Answer:

Explanation:
d = Diameter of spot = 30 μm
r = Radius of spot = 
P = Power of the laser = 
A = Area = 
Intensity is given by

The light intensity within this spot is 
Answer:
g/cm³
Explanation:
From the question given above,
The y-axis is representing mass (g)
The x-axis is representing volume (cm³)
Unit of slope =?
Slope of a graph is simply defined as the change in y-axis divided by the change in x-axis. Mathematically it is expressed as:
Slope = change in y-axis (Δy)/change in x-axis (Δx)
Slope = Δy/Δx
Thus, with the above formula, we can obtain the unit used for measuring the slope as follow:
y-axis = mass (g)
x-axis = volume (cm³)
Slope =.?
Slope = Δy/Δx
Slope = mass (g) /volume (cm³)
Slope = g/cm³
Therefore, the derive unit used for measuring the slope is g/cm³