When a 25-kg crate is pushed across a frictionless horizontal floor with a force of 200 N, directed 20 below the horizontal, th
e magnitude of the normal force of the floor on the crate isA. 25N
B. 68N
C. 180N
D. 250N
E. 310N
B. 68N
C. 180N
D. 250N
E. 310N
1 answer:
Answer:
Option E is correct 310N
Explanation:
Given that the force used to push the crate is F = 200N
The force directed 20° below the horizontal
Mass of crate is m = 25kg
Weight of the crate can be determine using
W = mg
g is gravitational constant =9.8m/s²
W = 25×9.8
W = 245 N
Check attachment. For free body diagram and better understanding
Using newton second law along the vertical axis since we want to find the normal force
ΣFy = m•ay
ay = 0, since the body is not moving in the vertical or y direction
N—W—F•Sin20 = 0
N = W+F•Sin20
N = 245+ 200Sin20
N = 245 + 68.4
N = 313.4 N
The normal force is approximately 310 N to the nearest ten
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Answer:
a. 0.000002 m
b. 0.00000182 m
Explanation:
36 cm = 0.36 m
15 cm = 0.15 m
a) We can start by calculating the air-water pressure of the bucket submerged 20m below the water surface:
Suppose air is ideal gas, then if the temperature stays the same, the product of its pressure and volume stays the same
Where P1 = 1.105 Pa is the atmospheric pressure, V_1 is the air volume in the bucket on the suface:
As the pressure increases, the air inside the bucket shrinks. But the crossection area stays constant, so only h, the height of air, decreases:
b) If the temperatures changes, we can still reuse the ideal gas equation above:
Answer:
18.5 m/s
Explanation:
On a horizontal curve, the frictional force provides the centripetal force that keeps the car in circular motion:
where
is the coefficient of static friction between the tires and the road
m is the mass of the car
g is the gravitational acceleration
v is the speed of the car
r is the radius of the curve
Re-arranging the equation,
And by substituting the data of the problem, we find the speed at which the car begins to skid:
Answer:
(D) 96 kg-m/s
Explanation:
Let's start off by first calculating the normal force between the box and the floor.
This will be:
Normal Force = 12 * 9.81 = 117.72 N
We can now use the friction equation to find the frictional force on the box when it is moving:
Frictional force = Coefficient of friction * Normal Force
Frictional force = 0.4 * 117.72 = 47.09 N
Finally, since we have the force on the box, we can find the acceleration:
F = Mass * Acceleration
47.09 = 12 * Acceleration
Acceleration = 3.92 m/s^2
Final speed after 2 seconds:
V= -3.84 m/s
Since we know the initial and final speeds, we can calculate the change in momentum:
Change in momentum = Final Momentum - Initial Momentum
Change in momentum =
Change in momentum = 94.08 kg*m/s
Thus we can see that option (D) is the closest answer.