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Darya [45]
3 years ago
6

a body starts from rest and moving under uniform acceleration of 4 metre per second square travel half of its total path during

last second of its motion find the time and total distance ​
Physics
1 answer:
lakkis [162]3 years ago
5 0

Answer:

t = 3.414 s

s = 23.3 m

Explanation:

Let t be the total time of motion

Let s be the total distance of motion

s - s/2 = ½at² - ½a(t - 1²) = ½a(t² - (t - 1)²)

s/2 = ½a(t² - (t² - 2t + 1)) = ½a(t² - t² + 2t - 1)

s = a(2t - 1)

s = 4(2t - 1)

s = 8t - 4

8t - 4 = ½4t²

8t - 4 = 2t²

0 = 2t² - 8t + 4

0 = t² - 4t + 2

t = (4 ±√(4² - 4(1)(2))) / 2 = (4 ± √8)/2 = 2 ± √2

t = 3.414 s

or

t = 0.5857... s which we ignore because it does not have a full last second.

s = ½(4)3.414² = 23.3137... 23.3 m

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In a US household, the voltage in an electric outlet (in volts) is given by the following equation, where t is in seconds. V = 1
Damm [24]

Answer:

a) The voltage in an european house is 2,17 times greater than in an american House. That is 183 volts more than in US.

b) the number of cycles or oscillations for an US House is 60 cycles per second

Explanation:

To answer this this question you have to know the wave equation:

x(t) = A Sin (a + b.t)

where

x(t) = is the position as a time function... In this exercise we could call V(t) instead of x(t) beacause we want to know voltage vs time.

A = is the amplitude of the wave. In this case the maximum voltage that can be reached.

a = is the offset in time or number of waves (zero in this exercise)

b =  constant that varies the frequency

then...

a) calculate the ratio between both amplitudes:

A_{Europe} / A_{US} = 339 / 156 = 2,17

b) frequency (Oscillations) is:

b = 2pi/T = 2pi*F    remember that: T = 1/F

where

F = frequency

T = Period

so for US household we have:

120pi =2pi*F

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F = 120/2 = 60 Hertz

5 0
4 years ago
Ellie is visiting the Grand Canyon on her summer vacation. Everyone in her tour group marvels at the different rock
PSYCHO15rus [73]

Answer: She could research what geologists have already discovered about the canyon.

She could hike into the canyon and make observations of the rocks in each layer.

She could compare her observations of the rock layers to other rock layers in the area.

3 0
3 years ago
Suppose a 60-kg boy and a 41-kg girl use a massless rope in a tug-of-war on an icy, resistance-free surface. If the acceleration
Digiron [165]

Answer:

Approximately 2.05\; {\rm m\cdot s^{-2}}.

Explanation:

The net force on the girl would be:

\begin{aligned}m(\text{girl}) \, a(\text{girl}) &= 41\; {\rm kg} \times 3.0\; {\rm m\cdot s^{-2}} \\ &= 123.0\; {\rm N} \end{aligned}.

Under the assumptions, the net force on this girl would be equal to the tension force in the rope. All other forces on the girl would be balanced.

In other words, the tension force that the rope exerted on the girl would be 123.0\; {\rm N}. The girl would exert a reaction force on the rope at the same magnitude (123.0\; {\rm N}\!) in the opposite direction. This force would translate to a 123.0\; {\rm N}\!\! force on the boy towards the girl.

Under similar assumptions, the net force on the boy would also be 123.0\; {\rm N}. Since the mass of the boy is m(\text{boy}) = 60\; {\rm kg}, the acceleration of the boy would be:

\begin{aligned}a(\text{boy}) &= \frac{(\text{net force})}{m(\text{boy})} \\ &= \frac{123.0\; {\rm N}}{60\; {\rm kg}} \\ &= 2.05\; {\rm m\cdot s^{-2}}\end{aligned}.

3 0
2 years ago
When electric current is flowing in a circuit, if the voltage applied to the circuit is increased, the
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<span>a. current will increase.       </span>
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3 years ago
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dexar [7]

Explanation:

Given:

y₀ = 22 m

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v² = (0 m/s)² + 2 (-9.8 m/s²) (1.5 m − 22 m)

v = -20.0 m/s

3 0
3 years ago
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