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IRISSAK [1]
3 years ago
10

A car speeds up as it rolls down a hill. which is this an example of? positive acceleration negative acceleration relative veloc

ity
Physics
2 answers:
alex41 [277]3 years ago
6 0
Positive acceleration
anzhelika [568]3 years ago
5 0
Positive acceleration
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A spring has a spring constant of 330 n/m. how far is the spring compressed when 150 newtons of force are used?
vitfil [10]

Answer:

b. 0.45 meters

Explanation:

Given the following data;

Spring constant, k = 330 N/m

Force = 150 N

To find the extension of the spring;

Mathematically, the force exerted on a spring is given by the formula;

Force = spring constant * extension

Substituting into the formula, we have;

150 = 330 * extension

Extension, e = 150/330

Extension, e = 0.45 meters

7 0
2 years ago
A record turntable is rotating at 33 rev/min. A watermelon seed is on the turntable 4.0 cm from the axis of rotation. (a) Calcul
Annette [7]

Answer:

a) a = 0.477 m/s^2

b) u = 0.04862

Explanation:

Given:-

- The rotational speed of the turntable N = 33 rev/min

- The watermelon seed is r = 4.0 cm away from axis of rotation.

Find:-

(a) Calculate the acceleration of the seed, assuming that it does not slip. (b) What is the minimum value of the coefficient of static friction between the seed and the turntable if the seed is not to slip

Solution:-

- First determine the angular speed (w) of the turntable.

                   w = 2π*N / 60

                   w = 2π*33 / 60

                   w = 3.456 rad/s

- The watermelon seed undergoes a centripetal acceleration ( α ) defined by:

                   α = w^2 * r

                   α = 3.456^2 * 0.04

                   α = 0.477 m / s^2

- The minimum friction force (Ff) is proportional to the contact force of the seed.

- The weight (W) of the seed with mass m acts downwards. The contact force (N) can be determined from static condition of seed in vertical direction.

                   N - W = 0

                   N = W = m*g

- The friction force of the (Ff) is directed towards the center of axis of rotation, while the centripetal force acts in opposite direction. The frictional force Ff = u*N = u*m*g must be enough to match the centripetal force exerted by the turntable on the seed.

                    Ff = m*a

                    u*m*g = m*a

                    u = a / g

                    u = 0.477 / 9.81

                    u = 0.04862

8 0
2 years ago
What are non-contact forces please include example in your answer
Alina [70]

Answer:

Gravitational force.  Magnetic force.  Electrostatics.  Nuclear force.

Explanation:

Apple falling from a tree

raindrops falling from the sky

4 0
3 years ago
Read 2 more answers
Five different forces act on an object. Is it possible for the net force on the object to be zero?
bazaltina [42]
No because there must be an even # if their is an even amount one of the forces isn’t being cancelled
4 0
2 years ago
WILL NAME THE BRAINLIEST! An airplane undergoes the following displacements: It first flies 72 km in a direction of 30° East of
nekit [7.7K]

Answer:

82.1 km

Explanation:

We need to resolve each displacement along two perpendicular directions: the east-west direction (let's label it with x) and the north-south direction (y). Resolving each vector:

A_x = (72) sin 30^{\circ} =36.0 km\\A_y = (72) cos 30^{\circ} = 62.4 km

Vector B is 48 km south, so:

B_x = 0\\B_y = -48

Finally, vector C:

C_x = -(100) cos 30^{\circ} =-86.6 km\\C_y = (100) sin 30^{\circ} = 50.0 km

Now we add the components along each direction:

R_x = A_x + B_x + C_x = 36.0 + 0 +(-86.6)=-50.6 km\\R_y = A_y+B_y+C_y = 62.4+(-48)+50.0=64.6 km

So, the resultant (which is the distance in a straight line between the starting point and the final point of the motion) is

R=\sqrt{R_x^2+R_y^2}=\sqrt{(-50.6)^2+(64.6)^2}=82.1 km

4 0
2 years ago
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