Joe rides his bicycle in a straight line for 2 hour with an average velocity of 13 km/h south, how far has he ridden?

In any homogeneous medium, the constant factor is a wave's:

eimsori [14]

answer is frequency

5 0

3 years ago

A ski lift has a one-way length of 1 km and a vertical rise of 200 m. The chairs are spaced 20 m apart, and each chair can seat

rusak2 [61]

Power is needed for (1) acceleration and (2) lifting the loaded chairs. These two parts can be calculated separately and then added together.

(1) Power for acceleration:

The final speed of the lift is

V=(10 km/h)(1 h×1000 m60 sec×1 km)=2.887 m/s.

Then the power needed is

Pa=12m(V2−V20)/Δt=12(50×250 kg)(2.778 m/s)2=9.6 kW.

(2) Power for lift

Assume that the acceleration is constant (i.e. power supply is constant), its value will be

a=ΔVΔt=2.778 m/s5 s=0.556 m/s2.

Then the vertical lift during acceleration will be

(12at2)×(2001000)=1.36 m.

Hence, the power needed to increase the potential energy of the lift is

Pg=mgΔhΔt=(50×250 kg) (9.89 m/s2)(1.36 m)/(5 s)=3.41 kW.

Then the total Power required is

Ptotal=Pa+Pg=9.6+34.1=43.7 kW.

Learn more about potential energy at

brainly.com/question/14427111

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4 0

2 years ago

A football player, with a mass of 69.0 kg, slides on the ground after being knocked down. At the start of the slide, the player

White raven [17]

Answer:

(a) -472.305 J

(b) 1 m

Explanation:

(a)

Change in mechanical energy equals change in kinetic energy

Kinetic energy is given by $0.5mv^{2}$

Initial kinetic energy is $0.5\times 69\times 3.7^{2}=472.305 J$

Since he finally comes to rest, final kinetic energy is zero because the final velocity is zero

Change in kinetic energy is given by final kinetic energy- initial kinetic energy hence

0-472.305 J=-472.305 J

(b)

From fundamental kinematic equation

$v^{2}=u^{2}+2as$

Where v and u are final and initial velocities respectively, a is acceleration, s is distance

Making s the subject we obtain

$s=\frac {v^{2}-u^{2}}{-2a}$ but a=\mu g hence

$s=\frac {v^{2}-u^{2}}{-2\mu g}=\frac {0^{2}-3.7^{2}}{-2*0.7*9.81}=0.996796272\approx 1 m$

7 0

3 years ago

The volleyball team practiced their serves, rotations, and ________. Which choice completes the sentence with correct parallel s

Phoenix [80]

Answer

Correct Answer is a.(spikes)

Explanation:

option a is correct because here serves, rotation and spikes all the three words are using as object.

The volleyball team practiced their serves, rotations, and spikes.

option b cannot be correct because here spiking is used as a verb and sentence(The volleyball team practiced their serves, ) is in past indefinite form and we cant use word spiking here because this form of verb is used in continues form of sentences only.

Option c cannot be correct as because in this option ""spikes the ball" spikes is used as a verb which can be used in present indefinite form of sentence only but here sentence is in past indefinite form.

Again option d cannot be correct because in this option ""spikes over the net" spikes is used as a verb which can be used in present indefinite form of sentence only but here sentence is in past indefinite form.

5 0

4 years ago

Read 2 more answers

565900 seconds into day

olasank [31]

The answer is 6 and a half days

3 0

4 years ago