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3 years ago

Ten Seconds after starting from rest, a car moving at 40 m/s what is the cars average acceleration

Physics

1 answer:

marta [7]3 years ago

6 0

Answer:

$4ms {}^{ - 2}$

Explanation:

We can use equation of motion to solve this

$v = u + at \\ 40 = 0 + a(10) \\ a = 4m {s}^{ - 2}$

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A plane starting at rest at one end of a runway undergoes a uniform acceleration of 4.8 m/s

yKpoI14uk [10]

initial velocity=0m/s=u
Acceleration=a=4.8m/s^2
Time=t=15s

Final velocity be v

$\\ \sf\longmapsto v=u+at$

$\\ \sf\longmapsto v=0+4.8(15)$

$\\ \sf\longmapsto v=72m/s$

8 0

3 years ago

A diver rises quickly to the surface from a 5.0 m depth. If she did not exhale the gas from her lunds before rising, by what fac

Inessa [10]

Answer:

1.5 times

Explanation:

$h$ = depth of the diver initially = 5 m

$\rho$ = density of seawater = 1030 kg m⁻³

$P_{i}$ = Initial pressure at the depth

$P_{f}$ = final pressure after rising = 101325 Pa

Initial pressure at the depth is given as

$P_{i} = P_{f} + \rho gh\\P_{i} = 101325 + (1030) (9.8) (5)\\P_{i} = 151795 Pa$

$V_{i}$ = Initial volume at the depth

$V_{f}$ = Final volume after rising

Since the temperature remains constant, we have

$P_{f} V_{f} = P_{i} V_{i}\\(101325) V_{f} = (151795) V_{i}\\V_{f} = 1.5 V_{i}$

6 0

3 years ago

A solid cylinder with a mass of 2.72 kg and a radius of 0.083 m starts from rest at a height of 4.20 m and rolls down a 88.7 ◦ s

Bingel [31]

Explanation:

According to the law of conservation of energy ,

Potential energy = kinetic energy

$mgh = \frac{1}{2} \times mv^{2} + \frac{1}{2} \times I \times \omega^{2}$

I = $\frac{mr^{2}}{2}$

$\omega = \frac{v}{r}$

$mgh = [\frac{1}{2} \times mv^{2}] + [\frac{1}{2} \times (\frac{mr^{2}}{2}) \frac{v^{2}}{r^{2}}]$

mgh = $[\frac{1}{2} \times mv^{2}] + [\frac{1}{4} \times mv^{2}]$

$g \times h = \frac{3}{4} \times v^{2}$

$9.8 \times 4.2 = \frac{3}{4} \times v^{2}$

v = 7.4 m/s

thus, we can conclude that the translational speed of the cylinder when it leaves the incline is 7.4 m/s.

5 0

3 years ago

A 1425 kg truck driving at 13.0 m/s collides elastically with a stationary 1175 kg car. If the car is traveling 14.25 m/s just a

TEA [102]

Answer:

1.25 m/s

Explanation:

m1v1+m2v2=m1v1f+m2v2f

(1425*13)+(1175*0)=(1425*v1f)+(1175*14.25)

18525+0=1425(v1f)+16743.75

1781.25=1425(v1f)

v1f=1.25 m/s

4 0

3 years ago

A tire measures 20 inches in diameter. How many revolutions will the tire have completed when it has traveled 100 yards? Express

Soloha48 [4]

<h2>Number of revolutions required to travel 100 yards is 57.</h2>

Explanation:

Diameter of tire,D = 20 inches

Perimeter of tire = πD

Perimeter of tire = π x 20 = 62.8 inches

Distance traveled = 100 yards

1 yard = 36 inches

Distance traveled = 100 x 36 = 3600 inches

In one revolution it travels 62.8 inches.

$\texttt{No of revolutions = }\frac{3600}{62.8}\\\\\texttt{No of revolutions = }57.32\\\\\texttt{No of revolutions = }57$

Number of revolutions required to travel 100 yards is 57.

8 0

3 years ago