A car has a speed of 20 m/s. If the speed of the car increases to 30 m/s in 5 seconds, what is the car’s acceleration?

Why do clothes often cling together after tumbling in a clothes dryer?

nadya68 [22]

Answer:

Explained

Explanation:

The electrons get rubbed off some items onto others. This causes an excess or electron on one item and deficiency of electron on the other. Therefore an electrostatic force of attraction is produced and hence clothes often cling together after tumbling in a clothes dryer

8 0

2 years ago

Consider the equation . The dimensions of the variables v, x, and t are , , and , respectively. The numerical factor 3 is dimens

Vinvika [58]

Answer:

Part of the question is missing but here is the equation for the function;

Consider the equation v = (1/3)zxt2. The dimensions of the variables v, x, and t are [L/T], [L], and [T] respectively.

Answer = The dimension for z = 1/T3 i.e 1/ T - raised to power 3

Explanation:

What is applied is the principle of dimensional homogenuity

From the equation V = (1/3)zxt2.

V has a dimension of [L/T]

x has a dimension of [L]

t has a dimension of [T]
from the equation, make z the subject of the relation
z = v/xt2 where 1/3 is treated as a constant
Substituting into the equation for z
z = L/T / L x T2
the dimension for z = 1/T3 i.e 1/ T - raised to power 3

5 0

2 years ago

An object has a mass of 60 kg. It decelerates from 50 m/s to 20 m/s when a resultant force of 300 N acts on it. For how long doe

Pavlova-9 [17]

Force=300N
Mass=60kg

Find Acceleration

$\\ \rm\longmapsto F=ma$

$\\ \rm\longmapsto a=\dfrac{F}{m}$

$\\ \rm\longmapsto a=\dfrac{-300}{60}$

$\\ \rm\longmapsto a=-5m/s^2$

Now

u=50m/s
v=20m/s

Using 1st equation of kinematics

$\\ \rm\longmapsto v=u+at$

$\\ \rm\longmapsto t=\dfrac{v-u}{a}$

$\\ \rm\longmapsto t=\dfrac{20-50}{-5}$

$\\ \rm\longmapsto t=\dfrac{-30}{-5}$

$\\ \rm\longmapsto t=6$

4 0

2 years ago

How are astronomers able to observe and study black holes?

Ber [7]

Although scientists can't detect or observe black holes with telescopes that detect x-rays, light, or other many other different forms of electromagnetic radiation and waves. But they can detect and study them by the effect of matter near it. If a black hole passes through a cloud of interstellar matter, it will draw matter inward (this process is known as accretion). A similar process occurs when a star passes through a black hole. When this happens, a star can break apart as it pulls it self toward it. As the attracted matter accelerates and starts heating up, it emits x-rays that are radiate into space.
Recent studies do show that black do have a very big influence towards neighborhoods around it. The black hole emits gamma ray bursts, devouring nearby stars, and spurring the growth of new stars in some areas while stalling it in others.

Info: https://science.nasa.gov/astrophysics/focus-areas/black-holes

Hope this Helps! (:

5 0

2 years ago

As a science fair project, you want to launch an 800 g model rocket st raight up and hit a horizontally moving target as it pass

fredd [130]

Sum the forces in the y (upward) direction

$\sum F_y = ma$