All categories

3 years ago

A glass falls off a shelf. How fast is the glass moving after 0.4 seconds?

Physics

2 answers:

Rufina [12.5K]3 years ago

8 0

Answer:

3.9 m/s

Explanation:

Apex ; good luck everyone! :)

tresset_1 [31]3 years ago

6 0

On Earth, gravity increases the speed of a falling object by about 9.8 m/s
every second that it falls.

In 0.4 second, its speed increases by (0.4 x 9.8) = 3.92 m/s.

If it just rolled off of the shelf at the beginning of that 0.4 second, then it
started from zero speed, and its speed after 0.4 second is 3.92 m/s.

Its velocity is 3.92 m/s downward.

You might be interested in

Select all of the answers that apply.

postnew [5]

Here are the answers to the given question above.
Relative dating uses laws or principles of stratigraphy and paleontology. These laws of relative dating are:
-law of original horizontality
-law of superposition
-law of original lateral continuity
-law of cross-cutting or intrusive relationships
Hope these are the answers that you are looking for.

3 0

3 years ago

Read 2 more answers

Two trains are headed towards each other on the same track unbeknownst to the engineers. One departs San Francisco. Its average

aalyn [17]

Answer:

7,166 hrs =430 minutes

Explanation:

Since both train are on the same track, going one towards the other, the relative speed is the addition of both, then the time they need to meet, and consistently crash, is the time that (65mph + 55 mph)=120mph need to travel the total distance of 860 miles, of course in this case one part is traveled by the first train and the rest by the other. Then to find the time we use a three rule

1 h --->120mi

X ---->860mi, then X=(860 mi* 1h)/120 mi = 43/6 hrs= 7,16666 hrs, turning this into minutes need that we notice 1h=60min, then 43/6 hrs *60 min/hrs = 430 minutes.

7 0

3 years ago

A 2.13-kg object on a frictionless horizontal track is attached to the end of a horizontal spring whose force constant is 5.00 N

ANTONII [103]

Answer:

17.54N in -x direction.

Explanation:

Amplitude (A) = 3.54m

Force constant (k) = 5N/m

Mass (m) = 2.13kg

Angular frequency ω = √(k/m)

ω = √(5/2.13)

ω = 1.53 rad/s

The force acting on the object F(t) = ?

F(t) = -mAω²cos(ωt)

F(t) = -2.13 * 3.54 * (1.53)² * cos (1.53 * 3.50)

F(t) = -17.65 * cos (5.355)

F(t) = -17.57N

The force is 17.57 in -x direction

5 0

4 years ago

1. A 100-kg crate is pulled across a warehouse floor using a rope with a force of 250 N at an angle of 45o from the horizontal.

harkovskaia [24]

Answer:

(a) The net force is 80.394 N

The acceleration of the crate is 0.804 m/s²

(b) the final velocity of the crate is 5.02 m/s

Explanation:

Given;

mass of the crate, m = 100 kg

applied force, F = 250 N

angle of inclination, θ = 45°

coefficient of friction, μ = 0.12

Applied force in y-direction, $F_y = Fsin \theta = 250sin45 = 176.78 \ N$

Applied force in x-direction, $F_x = Fcos \theta = 250cos45 = 176.78 \ N$

The normal force is calculated as;

N + Fy -W = 0

N = W - Fy

N = (100 x 9.8) - 176.78

N = 980 - 176.78 = 803.22 N

The frictional force is given by;

Fk = μN

Fk = 0.12 x 803.22

Fk = 96.386 N

(a) The net force is given by;

$F_{net} = F_x - F_k\\\\F_{net} = 176.78-96.386\\\\F_{net} = 80.394 \ N$

Apply Newton's second law of motion;

F = ma

$a = \frac{F_{net}}{m}\\\\ a = \frac{80.394}{100}\\\\ a = 0.804 \ m/s^2$

(b) the velocity of the crate after 5.0 s

$F = ma= \frac{m(v-u)}{t} \\\\Ft =m(v-u)\\\\v-u = \frac{Ft}{m}\\\\ v = \frac{Ft}{m} + u\\\\v = \frac{F_{net}*t}{m} + u\\\\v = \frac{80.394*5}{100} + 1\\\\v = 5.02 \ m/s$

7 0

3 years ago

Scientists have changed the model of the atom as they have gathered new evidence. One of the atomic models is shown below. Overl

olga55 [171]

Answer:

A). A few of the positive particles aimed at a gold foil seemed to bounce back off of the thin metallic foil.

Explanation:

Scientists decided to change the model of the atom when they discovered new evidence that showed 'few of the positive particles aimed at a gold foil seemed to bounce back off of the thin metallic foil.' On this ground, Rutherford concluded that atom is mostly made up of empty space and thus, he proposed a nucleus model of atom in which the atom comprises of the tiny and positively charged nucleus is surrounded by electrons with a negative charge. Thus, option A is the correct answer.

8 0

3 years ago

Read 2 more answers