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2 years ago

PLEASEEE HELPPPP

Physics

2 answers:

Evgen [1.6K]2 years ago

6 0

Answer:

The average car speed is 25.4 m/s

Explanation:

The definition of average speed is the total distance traveled between the total time

Vm = dx/dt (1)

To be able to use this equation let's calculate the total carriage distance

Xt = X1 + X2

X1 = 10 miles 1609 m / 1 miles = 16090 m

X2 = 10 miles 1609 m / 1miles = 16090 m

XT = 32180 m

Now let's calculate the total time

v = d / t

t = d / v

t1 = x1 / v1

t2 = x2 / v2

t1 = 16090/22

t1 = 731.36 s

t2 = 16090/30

t2 = 536.33 s

t all = t1 + t2

t all = 731.36 +536.33

t all = 1267.69 s

Having these values we use the initial equation

Vm = d / t

Vm = 32180 /1267.69

Vm = 25.38 m / s

The average car speed is 25.4 m/s

solniwko [45]2 years ago

5 0

Answer:

Explanation:

average speed more than 25.0m/s.

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Is it possible to have a net torque when all of the forces sum to zero? Explain.

nexus9112 [7]

Answer:

Yes it is possible

Explanation:

When two equal magnitude forces are acting on the rod in opposite direction

Then the net force on the system is always zero in that case

so we will have

$F - F = 0$

now for the system net torque due to these forces is given by

$\tau = F(r_1) + F(r_2)$

here we know that

$r_1, r_2$ = distance of the forces from reference about which torque is measured

so here we can say that net force is zero on the system while torque is not zero

in all such case object will rotate about a fixed position with change angular speed

3 0

3 years ago

An iron nail is driven into a block of ice by a single blow of a hammer. The hammerhead has a mass of 0.5 kg and an initial spee

larisa [96]

Answer:

The ice melts mass is:

$m_g=7.6x10^{-3} g$

Explanation:

Kinetic Energy

$K_E = 1/2*m*v^2$

$K_E = 1/2*0.5kg*(3.2m/s)^2$

$K_E=2.56 kg*m^2/s^2$

Heat gained by ice= mass(g) x 80 cal

( 1 cal = 4.184 *10^7er or g cm^2/ sec^2)

Assuming no loss in heat, in the motion so both continue with temperature 0~C

To find so the mass (gm) of ice melted

$m_g= 1/2 *(0.5*1000)*(3.2m/s)^2* 100*100 / (80*4.184*10^7)$

$m_g=7.6x10^{-3} g$

5 0

3 years ago

the average american receives 2.28 mSv dose equivalent from radon each year. Assuming you receive this dose, and it all comes fr

Dmitry [639]

Answer:

The approximate number of decays this represent is $N= 23*10^{10}$

Explanation:

From the question we are told that

The amount of Radiation received by an average american is $I_a = 2.28 \ mSv$

The source of the radiation is $S = 5.49 MeV \ alpha \ particle$

Generally

$1 \ J/kg = 1000 mSv$

Therefore $2.28 \ mSv = \frac{2.28}{1000} = 2.28 *10^{-3} J/kg$

Also $1eV = 1.602 *10^{-19}J$

Therefore $2.28*10^{-3} \frac{J}{kg} = 2.28*10^{-3} \frac{J}{kg} * \frac{1ev}{1.602*10^{-19} J} = 1.43*10^{16} ev/kg$

An Average american weighs 88.7 kg

The total energy received is mathematically evaluated as

$1 kg ------> 1.423*10^{16}ev \\88.7kg --------> x$

Cross-multiplying and making x the subject

$x = 88.7 * 1.423*10^{16} eV$

$x = 126.2*10^{16}eV$

Therefore the total energy deposited is $x = 126.2*10^{16}eV$

The approximate number of decays this represent is mathematically evaluated as

N = $\frac{x}{S}$

Where n is the approximate number of decay

Substituting values

$N = \frac{126 .2*10^{16}}{5.49*10^6}$

$N= 23*10^{10}$

7 0

3 years ago

1 point

Sav [38]

Answer:

388.5J

Explanation:

Given parameters:

Weight = 70N

Height = 5.55m

Unknown:

Gravitational potential energy at the top of the ladder = ?

Solution:

The gravitational potential energy is the energy due to the position of the body.

Gravitational potential energy = Weight x height

So;

Gravitational potential energy = 70 x 5.55 = 388.5J

8 0

2 years ago

If a sheep is running at 3.0 m/s with a mass of 60 kg what is its kinetic energy

borishaifa [10]

Answer:270joules

Explanation:KE = 1/2mv^2

KE = 1/2(60kg)(3.0)^2 = 270 Joules

8 0

3 years ago