All categories

3 years ago

Alessandra jumps on a trampoline. It takes her 1 second to

Physics

1 answer:

svp [43]3 years ago

5 0

Answer:

The speed of Alessandra's motion is 2 ft/s up.

Explanation:

Given that,

Time = 1 sec

Height = 2 feet

We need to calculate the speed of Alessandra's motion

Using formula of speed

$v=\dfrac{d}{t}$

Where, v = speed

d = height

t = time

Put the value into the formula

$v=\dfrac{2}{1}$

$v=2\ ft/s$

The direction will be up ward.

Hence, The speed of Alessandra's motion is 2 ft/s up.

(C) is correct option.

You might be interested in

How do weathering and erosion differ?

anzhelika [568]

Answer:

weathering breaks down the rocks while erosion moves them away from its original growth

7 0

3 years ago

Read 2 more answers

A mechanic needs to replace the motor for a merry-go-round. The merry-go-round should accelerate from rest to 1.5 rad/s in 7.0 s

marta [7]

Answer

given,

initial speed of merry-go-round = 0 rad/s

final speed of merry-go-round = 1.5 rad/s

time = 7 s

Radius of the disk = 6 m

Mass of the merry-go-round = 25000 Kg

Moment of inertia of the disk

$I = \dfrac{1}{2}MR^2$

$I = \dfrac{1}{2}\times 25000\times 6^2$

I = 450000 kg.m²

angular acceleration

$\alpha = \dfrac{\omega_f-\omega_0}{t}$

$\alpha = \dfrac{1.5-0}{7}$

$\alpha =0.214\ rad/s^2$

we know,

$\tau= I \alpha$

$\tau= 450000\times 0.214$

$\tau=96300\ N.m$

8 0

3 years ago

Describe how a battery works

Whitepunk [10]

Magic, Nah im just kidding. A battery has two parts, the anode and the cathode. Which anode is positive and cathode is negative, which they are connected to the electrolyte. Once they are connected to a device they once start working from separate ends. Which is the flow of energy

6 0

3 years ago

A 65.0 kg diver is 4.90 m above the water, falling at speed of 6.40 m/s. Calculate her kinetic energy as she hits the water. (Ne

mojhsa [17]

Answer:

4452.5 J.

Explanation:

The diver have both kinetic and potential energy.

Ek = 1/2mv² ................. Equation 1

Where Ek = Kinetic Energy of the diver, m = mass of the diver, v = velocity of the diver.

Given: m = 65 kg, v = 6.4 m/s.

Substitute into equation 1

Ek = 1/2(65)(6.4²)

Ek = 1331.2 J.

Also,

Ep = mgh ............................ Equation 2

Where Ep = Potential energy of the diver when its above the water, h = height of the diver above the water, g = acceleration due to gravity.

Given: m = 65 kg, h = 4.9 m, g = 9.8 m/s²

Substitute into equation 2.

Ep = 65(4.9)(9.8)

Ep = 3121.3 J.

Note: When she hits the water, the potential energy is converted to kinetic energy.

E = Ek+Ep

Where E = Kinetic energy of the diver when she hits the water.

E = 1331.2+3121.3

E = 4452.5 J.

3 0

3 years ago

How does Newton's second law apply to an "Egg Drop" experiment?

Black_prince [1.1K]

Because an object in rest stays in rest until an unequal force pushes it so gravity is pushing on the egg making it drop

6 0

3 years ago