Pls help it’s easy ik but I want to make sure of them both I don’t have much time

A force of 70 N is applied to a 28 kg rock causing it to slow down from 25 m/s to 15 m/s, a change in velocity of 10 m/s. How lo

maksim [4K]

Answer: 4 s

Explanation:

Given

The applied force is 70 N

mass of the rock is 28 kg

initial velocity $u=25\ m/s$

final velocity $v=15\ m/s$

Deceleration provided by force is

$a=-\dfrac{70}{28}=-2.5\ m/s^2$

using the equation of motion

$v=u+at\\\Rightarrow 15=25-2.5t\\\Rightarrow 2.5t=10\\\Rightarrow t=4\ s$

7 0

3 years ago

Consider two particles A and B. The angular position of particle A, with constant angular acceleration, depends on time accordin

Vera_Pavlovna [14]

Answer:

θ = θ₀ + ½ w₀ (t -t_1) + α (t -t_1)²

Explanation:

This is an angular kinematic exercise the equation for the angular position

the particle A

θ = θ₀ + ω₀ t + ½ α t²

They say for the particle B

w₀B = ½ w₀

αB = 2 α

In addition, the particle begins at a time t_1 after particle A, in order to use the same timer, we must subtract this time from the initial

t´ = t - t_1

l

et's write the equation of particle B

θ = θ₀ + w₀B t´ + ½ αB t´2

replace

θ = θ₀ + ½ w₀ (t -t_1) + ½ 2α (t -t_1)²

θ = θ₀ + ½ w₀ (t -t_1) + α (t -t_1)²

4 0

3 years ago

A student measures the volume of a gas sample at several different temperatures. The results are tabulated as follows:Temperatur

lapo4ka [179]

Answer:

Check the first and the third choices:

a. The temperature of a gas is directly proportional to its volume

b. The temperature-to-volume ratio of a gas is constant.

Explanation:

Rewrite the table for better understanding:

Temperature of gas (K) Volume of gas (L)

298 4.55

315 4.81

325 4.96

335 ?

Calculate the ratios temperature to volume with 3 significant figures:

298 / 4.55 = 65.5

315 / 4.81 = 65.5

325 / 4.96 = 65.5

Then, those numbers show a constant temperature-to-volume ratio, which may be expressed in a formula as:

Temperature / Volume = constant, which is a directly proportional variation (the volume increases in a constant proportion to the increase of the temperature).

Hence, the correct choices are:

The temperature of a gas is directly proportional to its volume (first statement), and

The emperature-to-volume ratio of a gas is constant (third statement).

5 0

4 years ago

Determine the slope of end a of the cantilevered beam. E = 200 gpa and i = 65. 0(106) mm4

DENIUS [597]

For E = 200 gpa and i = 65. 0(106) mm4, the slope of end a of the cantilevered beam is mathematically given as

A=0.0048rads

<h3>What is the slope of end a of the cantilevered beam?</h3>

Generally, the equation for the is mathematically given as

$A=\frac{PL^2}{2EI}+\frac{ML}{EI}$

Therefore

A=\frac{10+10^2+3^2}{2*240*10^9*65*10^6}+\frac{10+10^3*3}{240*10^9*65*10^{-6}}

A=0.00288+0.00192=0.0048rads

A=0.0048rads

In conclusion, the slope is

A=0.0048rads