The answer will b bc grass hopppers cant swin

A 0.300 kg block is pressed against a spring with a spring constant of 8050 N/m until the spring is compressed by 6.00 cm. When

natita [175]

Answer:

a) $\mu_{k} = 0.704$ , b) $R = 0.312\,m$

Explanation:

a) The minimum coeffcient of friction is computed by the following expression derived from the Principle of Energy Conservation:

$\frac{1}{2}\cdot k \cdot x^{2} = \mu_{k}\cdot m\cdot g \cdot \Delta s$

$\mu_{k} = \frac{k\cdot x^{2}}{2\cdot m\cdot g \cdot \Delta s}$

$\mu_{k} = \frac{\left(8050\,\frac{N}{m} \right)\cdot (0.06\,m)^{2}}{2\cdot (0.3\,kg)\cdot (9.807\,\frac{m}{s^{2}} )\cdot (7\,m)}$

$\mu_{k} = 0.704$

b) The speed of the block is determined by using the Principle of Energy Conservation:

$\frac{1}{2}\cdot k \cdot x^{2} = \frac{1}{2}\cdot m \cdot v^{2}$

$v = x\cdot \sqrt{\frac{k}{m} }$

$v = (0.06\,m)\cdot \sqrt{\frac{8050\,\frac{N}{m} }{0.3\,kg} }$

$v \approx 9.829\,\frac{m}{s}$

The radius of the circular loop is:

$\Sigma F_{r} = -90\,N -(0.3\,kg)\cdot (9.807\,\frac{m}{s^{2}} ) = -(0.3\,kg)\cdot \frac{v^{2}}{R}$

$\frac{\left(9.829\,\frac{m}{s}\right)^{2}}{R} = 309.807\,\frac{m}{s^{2}}$

$R = 0.312\,m$

5 0

3 years ago

To stop a car, first you require a certain reaction time to begin braking; then the car slows under the constant braking deceler

ANEK [815]

Answer:

a) $t_r = 0.55 s$

b) a = 5.59 m/s²

Explanation:

given,

total distance traveled by the car to stop is 56.9 m when speed of vehicle is 80 km/h or 80 × 0.278 = 22.24 m/s

total distance traveled by the car to stop is 25.7 m when speed of vehicle is 50.7 km/h or 50.7 × 0.278 = 14.09 m/s

using stopping distance formula

$s_1 = v_1 t_r +\dfrac{v_1^2}{2 a}$ ................(1)

$s_2 = v_2 t_r +\dfrac{v_2^2}{2 a}$ ..............(2)

on solving both the equation we get

$a = \dfarc{v_1v_2(v_1-v_2)}{2(s_1v_2-s_2v_1)}$

$a = \dfarc{22.4\times 14.09(22.24-14.09)}{2(56.9\times 14.09-25.7\times 22.24)}$

a = 5.59 m/s²

now reaction time calculation

$t_r =\dfrac{v_1^2d_2-v_2^2d_1}{v_1v_2(v_1-v_2)}$

$t_r =\dfrac{22.24^2\times 25.7-14.09^2\times 56.9}{22.4\times 14.09(22.24-14.09)}$

$t_r = 0.55 s$

8 0

3 years ago

A 50 kg woman, riding on a 10 kg cart, is moving east at 5.0 m/s. the woman jumps off the cart and hits the ground running at 7.

pav-90 [236]

To answer this question, we will use the law of conservation of momentum which states that:
(m1+m2)Vi = m1V1 + m2V2 where:
m1 is the mass of the woman = 50 kg
m2 is the mass of the cart = 10 kg
Vi is the initial velocity (of woman and cart combined) = 5 m/sec
V1 is the final velocity of the woman = 7 m/sec
V2 is the final velocity of the cart that we need to calculate

Substitute with the givens in the above equation to get the final velocity of the cart as follows:
(50+10)(5) = (50)(7) + (10)V2
10V2 = -50
V2 = -5 m/sec
Note that the negative sign indicates that the cart is moving in an opposite direction to the others.

4 0

3 years ago

g You want to make simultaneous measurements of the position and momentum of an electron and a proton that are moving along a st

Maslowich

Answer:

1832

Explanation:

From;

Δp Δx = h/4π

Δp = uncertainty in momentum

Δx = uncertainty in position

h= Plank's constant

But p =mv hence, Δp= Δmv

m= mass, v= velocity

mass of electron = 9.11 * 10^-31 Kg

Mass of proton = 1.67 * 10^-27 Kg

since m is a constant,

Δv = h/Δxm4π

For proton;

Δv = 6.6 * 10^-34/4 * 3.14 * 1.67 * 10^-27 * 1 * 10^-10

Δv = 315 ms-1

For electron;

Δv = 6.6 * 10^-34/4 * 3.14 * 9.11 * 10^-31 * 1 * 10^-10

Δv = 577000 ms-1

Ratio of uncertainty of electron to that of proton = 577000 ms-1/315 ms-1= 1832

7 0

2 years ago

The specific heat of a substance is 0.215 J/g°C. How much energy is required to raise the temperature of 20 g of the substance f

sergey [27]

Taking into account the definition of calorimetry and sensible heat, the amount of energy required is 68.8 J.

<h3>Calorimetry</h3>

Calorimetry is the measurement and calculation of the amounts of heat exchanged by a body or a system.

<h3>Sensible heat</h3>

Sensible heat is defined as the amount of heat that a body absorbs or releases without any changes in its physical state (phase change).

In this way, between heat and temperature there is a direct proportional relationship. The constant of proportionality depends on the substance that constitutes the body and its mass, and is the product of the specific heat by the mass of the body.

So, the equation that allows to calculate heat exchanges is:

Q = c× m× ΔT

where:

Q is the heat exchanged by a body of mass m.
c is the specific heat substance.
ΔT is the temperature variation.

<h3>Energy required in this case</h3>

In this case, you know:

Q= ?
c= 0.215 $\frac{J}{gC}$
m= 20 g
ΔT= Tfinal - Tinitial= 88 C - 72 C= 16 C

Replacing in the definition of sensible heat:

Q = 0.215 $\frac{J}{gC}$ × 20 g× 16 C

Solving:

Finally, the amount of energy required is 68.8 J.

Learn more about calorimetry:

<u>brainly.com/question/11586486?referrer=searchResults</u>

<u>brainly.com/question/24724338?referrer=searchResults</u>

6 0

2 years ago