Ask question

Ask question

All categories

zhannawk [14.2K]

3 years ago

13

It is 5.5 km from your home to the physics lab. As part of your physical fitness program, you could run that distance at 10 km/h

(which uses up energy at the rate of 700 W), or you could walk it leisurely at 3.0 km/h (which uses energy at 290 W).
Part A. Which choice would burn up more energy?
Part B. How much energy (in joules) would it burn?
Part C. Why is it that the more intense exercise actually burns up less energy than the less intense one?

1 answer:

stealth61 [152]3 years ago

6 0

Explanation:

Displacement = 5 km

A.

Converting km/h to m/s,

10 km/h * 1000 m/1 km * 1 h/3600 s

= 25/9 m/s

Remember,

700 watt = 700 J/s

Velocity = displacement/time

Time = 5000/(25/9)

= 1800 s

Energy = power * time

= 700 * 1800

= 1,260,000

= 1260 kJ

B.

Converting km/h to m/s,

3 km/h * 1000 m/1 km * 1 h/3600 s

= 5/6 m/s

290 watt = 290 J/s

Velocity = displacement/time

Time = 5000/(5/6)

= 6000 s

Energy = power * time

= 290 * 6000

= 1,740,000

= 1740 kJ

C.

Walking burns more energy; 1,740,000 joules. It burns more because you walk for a greater period of time.

You might be interested in

What causes a nucleus to become radioactive?

timurjin [86]

Answer:

Answer the strong nuclear force attracts and binds protons and makes the nucleus unstable

Explanation:

4 0

3 years ago

The spaceship Intergalactica lands on the surface of the uninhabited Pink Planet, which orbits a rather average star in the dist

Sidana [21]

Complete Question

The spaceship Intergalactica lands on the surface of the uninhabited Pink Planet, which orbits a rather average star in the distant Garbanzo Galaxy. A scouting party sets out to explore. The party's leader–a physicist, naturally–immediately makes a determination of the acceleration due to gravity on the Pink Planet's surface by means of a simple pendulum of length 1.08m. She sets the pendulum swinging, and her collaborators carefully count 101 complete cycles of oscillation during 2.00×102 s. What is the result? acceleration due to gravity:acceleration due to gravity: m/s2

Answer:

The acceleration due to gravity is $g = 167.2 \ m/s^2$

Explanation:

From the question we are told that

The length of the simple pendulum is $L = 1.081.08 \ m$

The number of cycles is $N = 101$

The time take is $t = 2.00 *10^{2 \ }s$

Generally the period of this oscillation is mathematically evaluated as

$T = \frac{N}{t }$

substituting values

$T = \frac{101}{2.0*10^2 }$

$T = 0.505 \ s$

The period of this oscillation is mathematically represented as

$T = 2 \pi \sqrt{\frac{l}{g} }$

making g the subject of the formula we have

$g = \frac{L}{[\frac{T}{2 \pi } ]^2 }$

$g = \frac{4 \pi ^2 L }{T^2 }$

Substituting values

$g = \frac{4 * 3.142 ^2 * 1.08 }{505.505^2 }$

$g = \frac{4 * 3.142 ^2 * 1.08 }{0.505^2 }$

$g = 167.2 \ m/s^2$

7 0

3 years ago

A fluid is any substance that can flow and take the shape of its container A) true B) false

Tpy6a [65]

Its true...water takes the shape of its container and it flows..please give me 5 stars and brainliest

7 0

3 years ago

Read 2 more answers

A car and a lorry are about to collide. When they collide the two vehicles become tightly locked together. The lorry is going at

BartSMP [9]

Answer:

The speed of the vehicles immediately after the collision is 5.84 m/s.

Explanation:

The speed of the vehicles after the collision can be found by conservation of linear momentum:

$p_{i} = p_{f}$

$m_{1}v_{1_{i}} + m_{2}v_{2_{i}} = m_{1}v_{1_{f}} + m_{2}v_{2_{f}}$

Where:

m₁: is the mass of the car = 0.5 ton = 500 kg

m₂: is the mass of the lorry = 9.5 ton = 9500 kg

$v_{1_{i}}$ : is the initial speed of the car = 40 km/h = 11.11 m/s

$v_{2_{i}}$ : is the initial speed of the lorry = 20 km/h = 5.56 m/s

$v_{1_{f}}$ : is the final speed of the car =?

$v_{2_{f}}$ : is the final speed of the lorry =?

Since the two vehicles become tightly locked together after the collision $v_{1_{f}}$ = $v_{2_{f}}$ :

$m_{1}v_{1_{i}} + m_{2}v_{2_{i}} = v(m_{1} + m_{2})$

$v = \frac{m_{1}v_{1_{i}} + m_{2}v_{2_{i}}}{m_{1} + m_{2}} = \frac{500 kg*11.11 m/s + 9500 kg*5.56 m/s}{500 kg + 9500 kg} = 5.84 m/s$

Therefore, the speed of the vehicles immediately after the collision is 5.84 m/s.

I hope it helps you!

8 0

2 years ago

For thousands of years people thought that heavier objects fell faster than lighter objects. In fact, this is something that we

Ostrovityanka [42]

Answer:

See below

Explanation:

Gallileo is CORRECT in a vacuum where there is<u> no air friction</u>

<u>air friction</u> affects same or different weight objects differently and will cause same-weight or different weight objects to fall at different speeds

6 0

2 years ago