Ask question

Ask question

All categories

3 years ago

13

An object is moving east, and its velocity changes from 65 m/s to 25 m/s in 10 seconds. Which describes the acceleration? negati

ve acceleration of 4 m/s2 positive acceleration of 4 m/s2 positive acceleration of 9 m/s2 negative acceleration of 9 m/s2

1 answer:

hammer [34]3 years ago

5 0

Answer:

we could use the formula, v=u+at,

65=25+a (10), a=4 , since the motion is declerating we have a=-4 m/s2

You might be interested in

8. An airplane of mass 8500 kg dives has an altitude of 15,000 m. It then dives steeply to an

Ivan

Answer:

333.5 MJ

Explanation:

ΔV = m·g·Δh

= 8500 · 9.81 · (15000-11000)

= 8500 · 9.81 · 4000

= 333 540 000

≈ 333.5 ·10⁶J = 333.5 MJ

8 0

3 years ago

A sample of polonium-210 was left for 414 days.

jenyasd209 [6]

Answer:

PO(1) = PO(0) / 2 1 refers to 1 half life of PO(0)

PO(2) = PO(1) / 2 = P(0) / 4 amount of PO left after 2 half-lives

PO(3) = PO(2) / 2 = PO(0) / 8 amount of PO left after 3 half-lives

414 da / 138 da = 3 3 half-lives pass in 414 da

PO(0) = 8 PO(3) = 8 * 1.45E-4 g = 1.16E-3 g = .00116 g after 414 days

6 0

3 years ago

What do crystal of table salt look like?

Pavel [41]

They look like tiny cubes. They are in a cubic form.

6 0

4 years ago

A baseball pitcher throws a baseball horizontally at a linear speed of 42.5 m/s (about 95 mi/h). Before being caught, the baseba

Xelga [282]

Answer:

$v_t=46.4532\ m.s^{-1}$

Explanation:

Given:

Linear horizontal speed of the ball, $v_x=42.5\ m.s^{-1}$

distance travelled by the ball, $x=17.4\ m$

angle rotated by the ball, $\theta=44.1\ rad$

radius of the ball, $r=3.67\ cm=0.0367\ m$

<u>the time for which the ball travels:</u>

$t=\frac{x}{v_x}$

$t=\frac{17.4}{42.5}$

$t=0.4094\ s$

<u>Angular speed of the ball:</u>

$\omega=\frac{\theta}{t}$

$\omega=\frac{44.1}{0.4094}$

$\omega=107.7155\ rad.s^{-1}$

<u>Now the tangential speed at the equator of the ball:</u>

$v_t=r.\omega+v_x$ (the tangential speed due to rotation and the linear speed are having the same direction)

$v_t=0.0367\times 107.7155+42.5$

$v_t=46.4532\ m.s^{-1}$

4 0

4 years ago

The three classes of rocks are sedimentary, metamorphic, and igneous. How are rocks classified into one of these three groups?

sattari [20]

Answer:

according to the method of their formation

Explanation:

7 0

4 years ago