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Bridget is riding her bicycle up a hill. Which statements are correct? Check all that apply.

Svetlanka [38]

Answer:

Bridget is transferring energy to the bicycle.

The bicycle is using energy to do work.

Bridget has kinetic energy.

The bicycle has potential energy.

The bicycle has mechanical energy.

Explanation:

Energy can be transformed from one form to another. A body possess kinetic energy due to virtue of its motion. Potential energy is possessed by a body due to virtue of its position. mechanical energy is the sum of potential energy and kinetic energy. Nuclear energy is produced when atoms split or two atoms fuse together.

When Bridget is riding bicycle up a hill. Energy involved is both kinetic energy due to motion and potential energy due to gain in height up the hill. Bridget is pedaling, hence he is transferring energy to the bicycle. Bridget is in motion along with the bicycle. Hence, both Bridget and Bicycle have kinetic energy and potential energy. We can say both have mechanical energy. Thus correct options are:

Bridget is transferring energy to the bicycle.

The bicycle is using energy to do work.

Bridget has kinetic energy.

The bicycle has potential energy.

The bicycle has mechanical energy.

3 0

3 years ago

Read 2 more answers

A mother hawk screeches as she dives at you. You recall from biology that female hawks screech at 785 Hz , but you hear the scre

Ludmilka [50]

Answer:

Speed of the hawk, v = 40.4 m/s

Explanation:

It is given that,

Exact frequency of the female, f = 785 Hz

Observed frequency of female, f' = 890 Hz

Speed of sound, v = 343 m/s

Let v' is the speed of the hawk. It is based on the concept of Doppler's effect. We know that when the object approaches you, its speed is given by :

$f'=f(\dfrac{v}{v-v'})$

$890=785\times (\dfrac{343}{343-v'})$

v' = 40.4 m/s

So, the speed of the hawk is 40.4 m/s. Hence, this is the required solution.

6 0

4 years ago

According to the pressure-flow hypothesis, why must sieve-tube elements in phloem be living cells?

Zigmanuir [339]

Base from the pressure-flow hypothesis, the sieve tube in the phloem should be living cells because sugars are transported across the membranes by the active transport which needs ATP that is produced during respiration. Hope this helps.

3 0

4 years ago

A car traveling at 24 m/s starts to decelerate steadily. It comes to a complete stop in 8 seconds. What is its acceleration?

aleksklad [387]

Formula for velocity:
V(t) = Vi + at
Where V(t) is velocity at time t, Vi is initital velocity, and a is acceleration.
Solving for a:
V(8) = Vi + a(8)
V(8) = 0 (car has stopped)
0 = 24 + 8a
-24 = 8a
a = -3 m/s/s

6 0

3 years ago

To maintain a constant speed, the force provided by a car's engine must equal the drag force plus the force of friction of the r

bogdanovich [222]

Answer:

Toyota Camry

F_d = 51.852 N

F_d = 100.042 N

Hummer H2

F_d = 412.0888 N

F_d = 8351.755 N

Explanation:

Given:

- The density of air p_air = 1.2 kg/m^3

- The drag force equals car's engine force.

Find:

- What are the drag forces in newtons at 80 km/h and 105 km/h for a Toyota Camry? (Drag area = 0.70 m2 and drag coefficient = 0.28.)

- What are the drag forces in newtons at 80 km/h and at 105 km/h for a Hummer H2? (Drag area = 2.44 m2 and drag coefficient = 0.57.)

Solution:

- The formula for drag force is given as follows:

F_d = 0.5*C_d*p_air*A*V^2

Where,

A : The drag Area m^2

C_d: The drag coefficient

V: Velocity m/s

a) Toyota Camry

C_d = 0.28 , A = 0.70 m^2 , V = 80 km/h = 22.222 m/s

Then compute the F_d drag force:

F_d = 0.5*0.28*1.2*0.70*(22.22)^2

F_d = 51.852 N

C_d = 0.28 , A = 0.70 m^2 , V = 105 km/h = 29.1667 m/s

Then compute the F_d drag force:

F_d = 0.5*0.28*1.2*0.70*(29.1667)^2

F_d = 100.042 N

b) Hummer H2

C_d = 0.57 , A = 2.44 m^2 , V = 80 km/h = 22.222 m/s

Then compute the F_d drag force:

F_d = 0.5*0.57*1.2*2.44*(22.22)^2

F_d = 412.0888 N

C_d = 0.28 , A = 0.70 m^2 , V = 105 km/h = 29.1667 m/s

Then compute the F_d drag force:

F_d = 0.5*0.57*1.2*2.44*(29.1667)^2

F_d = 8351.755 N

4 0

3 years ago