Ask question

Ask question

All categories

katen-ka-za [31]

2 years ago

7

A police car is traveling at a speed of 50 meters per second when it suddenly accelerates at a rate of 5 m/s2. How fast will the

car be going (final velocity) if it maintains that acceleration for 30 seconds

1 answer:

Virty [35]2 years ago

6 0

Answer:i don't know sorry good luck tho

Explanation: i have not learned it yet

You might be interested in

At the race track, one race car starts its engine with a resulting intensity level of 104.0 dB at point P. Then 6 more cars star

dem82 [27]

To solve the problem it is necessary to apply the concepts related to sound intensity. The most common approach to sound intensity measurement is to use the decibel scale:

$\beta (dB) = 10log_{10}(\frac{I}{I_0})$

Where,

$I_0 = 1*10^{-12}$ is a reference intensity. It is the lowest or threshold intensity of sound a person with normal hearing can perceive at a frequency of 1000 Hz.

I = Sound intensity

Our values are given by,

$\beta = 104dB$

$\#Autos = 7$

For each auto the intensity would be,

$104 = 10log\frac{I}{1*10^{-12}}$

$10.4= log_{10} (\frac{I}{10^{-12}})$

$10^{10.4}*10^{-12}=I$

$I = 0.02511W/m^2$

Therefore the sound intesity for the 7 autos is

$I= 7* 0.02511$

$I = 0.1748W/m^2$

The sound level for the 7 cars in dB is

$\beta (dB) = 10log_{10}(\frac{0.1748}{1*10^{-12}})$

$\beta (dB) = 112.42dB$

8 0

2 years ago

A man at point A directs his rowboat due north toward point B, straight across a river of width 100 m. The river current is due

prohojiy [21]

Answer:

1.35208 m/s

Explanation:

Speed of the boat = 0.75 m/s

Distance between the shores = 100 m

Time = Distance / Speed

$Time=\frac{100}{0.75}=133.33\ s$

Time taken by the boat to get across is 133.33 seconds

Point C is 150 m from B

Speed = Distance / Time

$Speed=\frac{150}{\frac{100}{0.75}}=1.125\ m/s$

Velocity of the water is 1.125 m/s

From Pythagoras theorem

$c=\sqrt{0.75^2+1.125^2}\\\Rightarrow c=1.35208\ m/s$

So, the man's velocity relative to the shore is 1.35208 m/s

3 0

2 years ago

A box has a mass of 400 g. What minimum force is needed to lift it?

mart [117]

Answer: 3.92 N.

Explanation:

Your box weighs 400g, or 0.4kg. In order to lift it, you need to overcome the force of gravity. F = ma, and acceleration due to gravity is -9.8 m/s^2. So gravity acts on the box with a force of 0.4 kg * -9.8 m/s^2 = -3.92 N. A force of +3.92 N is required to overcome this.

5 0

2 years ago

A person is walking briskly in a straight line. The figure shows a graph of the person’s position x as a function of time t. Wha

Nina [5.8K]

The average velocity over the interval $6\le t\le 10$ is

$\dfrac{x(10)-x(6)}{10\,\mathrm s-6\,\mathrm s}=\dfrac{6\,\mathrm m-2.67\,\mathrm m}{4\,\mathrm s}=0.8325\,\dfrac{\mathrm m}{\mathrm s}$

where $x(t)$ is the person's position at time $t$ . I've taken the liberty of estimating $x(6)\approx2.67\,\mathrm m$ . The closest choice among the answers is $0.8\,\dfrac{\mathrm m}{\mathrm s}$ .

7 0

2 years ago

You work at a garden store for the summer, and you lift a 14 kg bag of fertilizer with a force of 227 N.

nika2105 [10]

Answer:

(a) Acceleration of the bag will be a=16.214m/sec^2

(B) Weight of the bag will be 137.2 N

Explanation:

We have given mass of the bag m = 14 kg

Force with which bag is lifted = 227 N

(A) According to newtons law we force is equal to F = ma , here m is mass and a is acceleration

So $227=14\times a$

$a=16.214m/sec^2$

(b) Acceleration due to gravity $g=9.8m/sec^2$

We know that weight is given by W = mg , here m is mass and g is acceleration due to gravity

So weight $W=mg=14\times 9.8=137.2N$

So weight of the bag will be 137.2 N

8 0

2 years ago