Answer:
Explanation:
mass of refrigerator, m = 110 kg
coefficient of static friction, μs = 0.85
coefficient of kinetic friction, μk = 0.59
(a) the minimum force required to just start the motion in refrigerator
F = μs x mg
F = 0.85 x 110 x 9.8
F = 916.3 N
(b) The force required to move the refrigerator with constant speed
F' = μk x mg
F' = 0.59 x 110 x 9.8
F' = 636.02 N
(c) Let a be the acceleration.
Net force = Applied force - friction force
F net = 950 - 636.02
F net = 313.98 N
a = F net / mass
a = 313.98 / 110
a = 2.85 m/s²
Answer:
11 m/s
Explanation:
Draw a free body diagram. There are two forces acting on the car:
Weigh force mg pulling down
Normal force N pushing perpendicular to the incline
Sum the forces in the +y direction:
∑F = ma
N cos θ − mg = 0
N = mg / cos θ
Sum the forces in the radial (+x) direction:
∑F = ma
N sin θ = m v² / r
Substitute and solve for v:
(mg / cos θ) sin θ = m v² / r
g tan θ = v² / r
v = √(gr tan θ)
Plug in values:
v = √(9.8 m/s² × 48 m × tan 15°)
v = 11.2 m/s
Rounded to 2 significant figures, the maximum speed is 11 m/s.
Answer:
Explanation:
b) Gravity reduces the initial upward velocity to zero in a time of
t = v/g = 40/10 = 4 s
a) h = v₀t + ½gt² = 40(4) + ½(-10)4² = 80 m
or
v² = u² + 2as
h = (0² - 40²) / 2(-10) = 80 m
The magnification of the ornament is 0.25
To calculate the magnification of the ornament, first, we need to find the image distance.
Formula:
- 1/f = u⁻¹+v⁻¹.................... Equation 1
Where:
- f = Focal length of the ornament
- u = image distance
- v = object distance.
make u the subject of the equation
- u = fv/(f+v)................ Equation 2
From the question,
Given:
Substitute these values into equation 2
- u = (12×4)/(12+4)
- u = 48/16
- u = 3 cm.
Finally, to get the magnification of the ornament, we use the formula below.
- M = u/v.................. Equation 3
Where
- M = magnification of the ornament.
Substitute these values above into equation 3
Hence, The magnification of the ornament is 0.25
