Help! <br><br> I need to do this quickly!!!

Acceleration refers to any changes in

Reptile [31]

Answer:

speed

Explanation:

6 0

2 years ago

A cement block accidentally falls from rest from the ledge of a 53.0-m-high building. When the block is 14.0 m above the ground,

katrin [286]

Answer:

0.405 seconds

Explanation:

Consider the amount of time it takes the block to fall from 53 m up to 14 m above the ground; then consider the amount of time it takes the block to fall from 53 m up to 2 m above the ground.

First, d = (1/2) gt^2 or t= ( 2 d / g)^1/2

= ( 2 × 39 / 9.8)^1/2 = 2.8212 seconds

Then, to fall from 53 down to 2 meters...

d = (1/2) gt^2 or t= ( 2 d / g)^1/2

= ( 2 * 51/ 9.8 )^1/2 = 3.2262 seconds

So the amount of time it takes for the block to fall from 14 m upto 2 m above the ground

3.2262 - 2.8212 = 0.405 seconds

this is how much time there is from when the man sees the block until it hits him. Not much time...

5 0

2 years ago

a single 1,300 jk cargo car is rolling along a train track at 2.0 m/s when 400 kg of coal is dropped vertically into it. what is

tensa zangetsu [6.8K]

Answer:

1.53 m/s

Explanation:

Given:

Mass of the car (M) = 1300 kg

Mass of the coal (m) = 400 kg

Initial velocity of the car (U) = 2 m/s

Initial velocity of the coal (u) = 0 m/s (Since it is dropped)

When the coal is dropped into the car, then they move with same final velocity.

Let the final velocity be 'v' m/s.

For a closed system, the law of conservation of momentum holds true.

So, initial momentum is equal to final momentum of the car-coal system.

Initial momentum of the car = $MU=1300\times 2=2600\ Ns$

Initial momentum of the coal = $mu=0\ Ns$

Total initial momentum is the sum of the above two momentums.

So, total initial momentum = 2600 + 0 = 2600 Ns

Now, final momentum is given as the product of combined mass and final velocity. So,

Final momentum of the system = $(M+m)v=(1300+400)v=1700v$

Now, from law of conservation of momentum,

Initial momentum = Final momentum

$2600=1700v\\\\v=\frac{2600}{1700}\\\\v=1.53\ m/s$

Therefore, the final velocity of either of the two masses is same is equal to 1.53 m/s.

4 0

2 years ago

A bank offers a credit plan that lists 2% interest for the first year of a loan. If a customer takes the loan and 16 years later

Bumek [7]

If the interest rate hasn't changed over the course of 16 years,
then that's pretty convincing evidence to suggest that the loan
has an fixed rate.

8 0

2 years ago

To protect their young in the nest, peregrine falcons will fly into birds of prey (such as ravens) at high speed. in one such ep

lozanna [386]

<span>The momentum of the falcon before collision is 0.6 * 20 = 12000 kgm/s which is actually the momenum of the falcon in the x-component. I had converted 600g to kg. After the collision the x-component of the raven is now mv2cos(thetha) where v2 is the final velocity of the raven and theta is the angle at which the falcon hits the raven. So we have that the falcon's final velocity = 600 * 5 * cos (theta). Likewise, after getting hit the the falcon, the raven's final momentum of is = m2v2cos(theta) = 1.5 * 9 * cos(theta). There's no motion along the y-components. So equating we have, momentum before collision = momentum after collision of the raven + momentum after collision of the falcon. So we have 12000 = 3000cos(theta) + 13.5cos(theta). Cos(theta)(3000 + 13.5) = 12000. Theta = cos^-1( 12000/3013.5 = 3.98 So theta =</span>

7 0

2 years ago

Help! I need to do this quickly!!!