Answer:
Magnitude of the force is 2601.9 N
Explanation:
m = 450 kg
coefficient of static friction μs = 0.73
coefficient of kinetic friction is μk = 0.59
The force required to start crate moving is
.
but once crate starts moving the force of friction is reduced
.
Hence to keep crate moving at constant velocity we have to reduce the force pushing crate ie
.
Then the above pushing force will equal the frictional force due to kinetic friction and constant velocity is possible as forces are balanced.
Magnitude of the force

Answer:
a. 1.75 Nm²/C
b. Yes.
Explanation:
a. Electric Flux is given as:
Φ = E*A*cosθ
Where E = electric flux
A = Surface area
Φ = 14 * 0.25 * cos60
Φ = 1.75 Nm²/C
b. Yes, the shape of the sheet will affect the Flux through it. This is because flux is dependent on area of the surface and the area is dependent on the shape of the surface.
Answer:

It will take 10 seconds to travel 200m at a speed of 10m/s
Explanation:
HOPE THAT THIS IS HELPFUL.
HAVE A GREAT DAY.
Answer:
the number of photons of yellow light does the lamp generate in 1.0 s is 7 x 
Explanation:
given information:
power, P = 25 W
wavelength. λ - 580 nm = 5.80 x
m
time, t = 1 s
to calculate the number of photon(N), we use the following equation
N = λPt/hc
where
λ = wavelength (m)
P = power (W)
t = time interval (s)
h = Planck's constant (6.23 x
Js)
c = light's velocity (3 x
)
So,
N = λPt/hc
= (5.80 x
)(25)(1)/(6.23 x
)(3 x
)
= 7 x 
Did you try looking it up ?