All categories

3 years ago

4. Jimmy dropped a 10 kg bowling ball from a building that is 25 meters high.

Physics

1 answer:

KIM [24]3 years ago

3 0

Answer:

The K.E of the bowling ball right before it hits the ground, K.E = 2450 J

Explanation:

Given data,

The mass of the bowling ball, m = 10 kg

The height of the building, h = 25 m

The total mechanical energy of the body is given by,

E = P.E + K.E

At height 'h' the P.E is maximum and the K.E is zero,

According to the law of conservation of energy, the K.E at the ground before hitting the ground is equal to the P.E at 'h'

Therefore, P.E at 'h'

P.E = mgh

= 10 x 9.8 x 25

= 2450 J

Hence, the K.E of the bowling ball right before it hits the ground, K.E = 2450 J

You might be interested in

Four monitoring wells have been placed around a leaking underground storage tank. The wells are located at the corners of a 1-ha

Readme [11.4K]

Answer:

direction : West to East

magnitude : 6.0 * 10^-3

Explanation:

Given data :

Four ( 4 ) monitoring wells

location of wells = corners of 1-ha square

Total piezometric head in each well ;

NE corner = 30.0 m ;

SE corner = 30.0 m;

SW corner = 30.6 m;

NW corner = 30.6 m.

Calculate for the magnitude and direction of the hydraulic gradient

first step ; calculate for area

Area = ( 1 -ha ) ( 10^4 m^2/ha )

= 1 * 10^4 m^2

Distance between the wells = length of side

= √( 1 * 10^4 ) m^2

= 100 m

Direction of Hydraulic gradient is from west to east because the total piezometric head in the west = Total piezometric head in the east

Next determine The magnitude of the hydraulic gradient

= ( 30.6 - 30 ) / 100

= 6.0 * 10^-3

8 0

3 years ago

A girl starts from rest and reaches a walking speed of 1.4 m/s in 3.0 s. She walks at this speed for 6.0 s. The girl then slows

Alona [7]

Answer:

1) The girl's acceleration at time 't' is, $a=0.47$ m/s²

2) The girl's acceleration at time 't₁' is, $a_{1}=0$ m/s²

3) The girl's acceleration at time 't₂' is, $a_{2}=-0.14$ m/s²

Explanation:

Given data,

The initial walking speed of the girl, u = 0

The speed of the girl at the time 't' 3 s is, v₁ = 1.4 m/s

The time period the girl walked at the speed 1.4 m/s is, t₁ = 6 s

The girl slows down and comes to a stop during a period, t₂ = 10 s

1) The girl's acceleration at time 't'

$a=\frac{v-u}{t}$

$a=\frac{1.4-0}{3}$

$a=0.47$ m/s²

2) The girl's acceleration at time 't₁'

$a_{1} =\frac{v_{1} -v}{t_{1}}$

$a_{1}=\frac{1.4-1.4}{6}$

$a_{1}=0$ m/s²

3) The girl's acceleration at time 't₂'

$a_{2} =\frac{v_{2} -v_{1}}{t_{2}}$

$a_{2}=\frac{0-1.4}{10}$

$a_{2}=-0.14$ m/s²

4 0

3 years ago

How is the Sun similar to the stars that can be seen at night?

prisoha [69]

Answer:

Explanation:

4 0

3 years ago

Read 2 more answers

7. A car travels a certain distance with a speed of

goblinko [34]

Let distance be x.

Time in going, t 1 = x/50

Time in coming, t 2 = x/40

Total time T = x/40 +x/50 = 9x/200

Average speed = total distance/ total time

=( x+x)/(9x/200)= 2x ×200/9x = 400/9 = 44.44 km/h

5 0

3 years ago

Why can't theories become laws?

shtirl [24]

Since each serves a different purpose, theories cannot become laws. Explaining how or why a natural phenomenon occurs is what the set of ideas called theories do. On the other hand, mathematical relationships that describes what happens are what is done by laws.

Let me show an example that illustrates the points. Describing what happens in the natural world are done by the mathematical formulas called the Gas Laws. In this example, it would show that by using the Gas Laws, I will be able to predict with great accuracy the pressure if I double the temperature of a sealed gas. This idea is a law since the relationship is mathematical and it tells us what will happen.

On the other hand, in order to explain why gases behave like the way they do, we must use the kinetic molecular theory.

7 0

3 years ago