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3 years ago

Sitting in a chairlift, Rebecca has a gravitational potential energy of 5,997.6

Physics

1 answer:

stira [4]3 years ago

8 0

Answer:

B) 12 m

Explanation:

Gravitational potential energy is:

PE = mgh

Given PE = 5997.6 J, and m = 51 kg:

5997.6 J = (51 kg) (9.8 m/s²) h

h = 12 m

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During the last shot of the game, the basketball goes from rest to 15 m/s and reaches the backboard in 0.41 s. What was the acce

Mrrafil [7]

Answer:

When you climb, earth exerts gravitational force on pack in downward direction(pointing towards the center of earth).

In order to climb, you need to work against work done by gravity on the pack.

Hence work done by you = work done by gravity on pack

= Force x displacement = 70 x 30 = 2100 J.

So you need to do 2100 joules of work to lift your pack.

Power is the rate of work done.

Therefore power = work done by you/time(in seconds)

= 2100/600 =3.5 watts

Explanation:

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3 years ago

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Which statement is true regarding a chemical reaction?

alina1380 [7]

Answer:

B) The total number of atoms does not change, so mass is conserved in the reaction.

Explanation:

According to the Law of Conservation of Mass, no matter can ever be created or destroyed. The number of atoms does not change, thus the mass does not change.

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3 years ago

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A go-cart and rider have a mass of 14 kg. If the cart accelerates at 6m/s^2 during a 40 m sprint in 100 seconds, how much power

lara [203]

Answer:

P = 33.6 [N]

Explanation:

To solve this problem we must use Newton's second law, which tells us that the sum of forces on a body is equal to the product of mass by acceleration.

∑F = m*a

where:

F = forces [N]

m = mass = 14 [kg]

a = acceleration = 6 [m/s²]

$F = 14*6\\F = 84 [N]$

In the second part of this problem we must find the work done, where the work in physics is known as the product of force by distance, it is important to make it clear that force must be applied in the direction of movement.

$W = F*d$

where:

W = work [J]

F = force = 84 [N]

d = displaciment = 40 [m]

$W = 84*40\\W = 3360 [J]$

Finally, the power can be calculated by the relationship between the work performed in a given time interval.

$P=W/t\\$

where:

P = power [W]

W = work = 3360 [J]

t = time = 100 [s]

Now replacing:

$P=3360/100\\P=33.6[W]$

The power is given in watts

3 0

3 years ago

A thin Nichrome wire connected to an ammeter surrounds a region of time-varying magnetic flux, and the ammeter reads 13 amperes.

Semenov [28]

Answer:

The current would be same in both situation.

Explanation:

Given that,

Current I = 13 A

Number of turns = 23

We need to calculate the induced emf

Using formula of induced emf is

$\epsilon=NA\dfrac{dB}{dt}$

For N = 1

$\epsilon=A\dfrac{dB}{dt}$

We need to calculate the current

Using formula of current

$i=\dfrac{\epsilon}{R}$

Put the value of emf

$i=\dfrac{A\dfrac{dB}{dt}}{R}$

Now, if the number of turn is 22 , then induced emf would be

$\epsilon'=NA\dfrac{dB}{dt}$

Then the current would be

$i'=\dfrac{\epsilon'}{NR}$

$i'=\dfrac{NA\dfrac{dB}{dt}}{NR}$

$i'=\dfrac{A\dfrac{dB}{dt}}{R}$

$i'=i$

Hence, The current would be same in both situation.

4 0

3 years ago

A baseball has a momentum of 6.0 kg.m/s south and mass of 0.15kg. What’s the baseballs velocity?

Mashcka [7]

Answer:

v=40 m/s south

Explanation:

Momentum

It's a physical magnitude that measures the product of the mass by the velocity of a particle. Its units in the International System is kg.m/s and the formula is

$p=m.v$

Where m is the mass and v the velocity of the particle. If we wanted to solve for v, we have

$\displaystyle v=\frac{p}{m}$

The baseball has a momentum of 6.0 kg.m/s south and mass of 0.15kg, thus

$\displaystyle v=\frac{6}{0.15}=40\ m/s$

The velocity is directed to the south

3 0

4 years ago