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3 years ago

A race car accelerates from 0 m/s to 20.0 m/s with a displacement of 35.0 m. What is the vehicle's acceleration?

Physics

1 answer:

shutvik [7]3 years ago

4 0

Explanation:

<u>Using Equations of Motion</u> :

${v}^{2} = {u}^{2} + 2as$

$a = \frac{{v}^{2} - {u}^{2}}{2s} = \frac{400 - 0}{70} = 5.71msec^{ - 2}$

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One end of a string is fixed. An object attached to the other end moves on a horizontal plane with uniform circular motion of ra

sveticcg [70]

Answer:

If both the radius and frequency are doubled, then the tension is increased 8 times.

Explanation:

The radial acceleration ( $a_{r}$ ), measured in meters per square second, experimented by the moving end of the string is determined by the following kinematic formula:

$a_{r} = 4\pi^{2}\cdot f^{2}\cdot R$ (1)

Where:

$f$ - Frequency, measured in hertz.

$R$ - Radius of rotation, measured in meters.

From Second Newton's Law, the centripetal acceleration is due to the existence of tension ( $T$ ), measured in newtons, through the string, then we derive the following model:

$\Sigma F = T = m\cdot a_{r}$ (2)

Where $m$ is the mass of the object, measured in kilograms.

By applying (1) in (2), we have the following formula:

$T = 4\pi^{2}\cdot m\cdot f^{2}\cdot R$ (3)

From where we conclude that tension is directly proportional to the radius and the square of frequency. Then, if radius and frequency are doubled, then the ratio between tensions is:

$\frac{T_{2}}{T_{1}} = \left(\frac{f_{2}}{f_{1}} \right)^{2}\cdot \left(\frac{R_{2}}{R_{1}} \right)$ (4)

$\frac{T_{2}}{T_{1}} = 4\cdot 2$

$\frac{T_{2}}{T_{1}} = 8$

If both the radius and frequency are doubled, then the tension is increased 8 times.

5 0

3 years ago

A cannonball is launched from the ground with 48279 Joules of kinetic energy. How much gravitational potential energy will the c

Mamont248 [21]

When the cannonball is shot upwards, kinetic energy converts to gravitational potential energy (GPE).

As the ball rises, speed decreases and height increases.

So when the cannonball has reached its maximum height, all of the Kinetic energy has transferred into gravitational potential energy.

(Because at the max height, the cannonball for a brief moment has no velocity, and thus no kinetic energy)

So the GPE is 48279 Joules at it's maximum height.

6 0

4 years ago

Use vector notation to describe the points that lie in the configuration. (Let s and t be elements of the Reals). the plane span

aniked [119]

Answer:

The answer is l(s, t) = (2s,7s + 2t,7t)

Explanation:

A general vector notation that can describe the points which lie in the configuration of the plane spanned by v1 and v2, is evaluated, thus:

V = v1 + v2

Where s and t are the elements of v1(2,7,0) and v2(0,2,7), respectively, and projected in x, y and z coordinates, we have:

V = sv1 + sv2, implying that:

V = (2sx + 7sy + 0sz) + (0tx + 2ty + 7tz)

Or, V= (2sx + 7sy) + (2ty + 7 tz)

Therefore, V = (2s,7s + 2t,7t)

and l(s, t) = (2s,7s + 2t,7t).

5 0

3 years ago

A coil spring stretches by 2.50 cm when a mass of 750 g is suspended from it. (a) Find the force constant of the spring. (b) How

weqwewe [10]

Answer:

(a) 294 N/m

(b) 0.027 m or 2.7 cm

Explanation:

(a) From Hook's law,

F = ke......................... Equation 1.

make k the subject of the equation

k = F/e..................... Equation 2

Where F = force applied on the spring, k = spring constant, e = extension.

From the question, the force applied to the spring is the weight of the mass.

F = mg = 0.75(9.8) = 7.35 N

Also, e = 2.5 cm = 0.025 m

Substitute these values into equation 2

k = 7.35/0.025

k = 294 N/m.

(b) If a mass of 800 g is suspended,

F = ke

e = F/k................... Equation 3

F = mg = 0.8(9.8) = 7.84 N,

k = 294 N/m.

Substitute these values into equation 3

e = 7.84/294

e = 0.027 m

e = 2.7 cm

7 0

3 years ago

True/False

Travka [436]

Answer:

True

Explanation:

5 0

3 years ago