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3 years ago

If a motorcycle accelerates uniformly from rest at 5 m / s2, how long does it take for it to reach a speed of 20 m / s.

Physics

1 answer:

irina1246 [14]3 years ago

6 0

Answer:

4 seconds

Explanation:

Given:

v₀ = 0 m/s

v = 20 m/s

a = 5 m/s²

Find: t

v = at + v₀

20 m/s = (5 m/s²) t + 0 m/s

t = 4 s

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9. What is the gravitational potential energy of a 61.2 kg person standing on the roof of a 10-storey building? (Each storey is

kow [346]

Answer:

15009

Explanation:

PE = mgh

PE = 61.2(9.81)(10 * 2.50)

PE = 15009.3

3 0

2 years ago

Given a particle that has the velocity v(t) = 3 cos(mt) = 3 cos (0.5t) meters, a. Find the acceleration at 3 seconds. b. Find th

dalvyx [7]

Answer:

Explanation:

a ) V = 3 cos(0.5t)

differentiating with respect to t

dv /dt = -3 x .5 sin0.5t

= -1.5 sin0.5t.

acceleration = - 1.5 sin 0.5t

when t = 3 s

acceleration = - 1.5 sin 1.5

= - 1.496 ms⁻²

v = 3 cos.5t

b ) dx/dt = 3 cos 0.5 t

dx = 3 cos 0.5 t dt

integrating on both sides

x = 3 sin .5t / .5

x = 6 sin0.5t

At t = 2 s

x = 6 sin 1

x = 5.05 m

4 0

3 years ago

Nicolaus Copernicus was a Polish astronomer who is best known for the theory that the sun is near the center of the universe and

serg [7]

Answer:

DOUBLE CHECK BECUASE IM ONLY 68.030303039999999% SURE!!!

(ANSWER IS HERE) ( D) It lacked practical examples in supporting theory

Know it's not B becuase there was no scientific community back then.

Know it's not C becuase it actully had lots of evidence.

But I'm not sure about A

3 0

3 years ago

A jet can travel the 6000 km distance between washington,

Andrei [34K]

<span> d = r*t is the basic distance equation
d = 6000 km
t with the tail wind = 6 hr
r with the tail wind = speed of the plane + wind speed = s + w
t with the head wind = 7.5 hr
r with the head wind = speed of the plane - wind speed = s-w
(s+w)*6 = 6000
(s-w)*7.5 = 6000
s + w = 1000
s - w = 800
</span><span> 2s = 1800
s = 900 km/h
s + w = 1000
w = 100
Check the anwer by calculating the return trip.
(900-100) * 7.5 = 800 * 7.5
800 * 7.5 = 6000 km
Answer: The rate of the jet in still air is 900 km/h. The rate of the wind is 100 km/hr.</span>

6 0

3 years ago

A jogger travels a route that has two parts. The first is a displacement of 3 km due south, and the second involves a displaceme

spayn [35]

Answer:

a) 2.41 km

b) 38.8°

Questions c and d are illegible.

Explanation:

We can express the displacements as vectors with origin on the point he started (0, 0).

When he traveled south he moved to (-3, 0).

When he moved east he moved to (-3, x)

The magnitude of the total displacement is found with Pythagoras theorem:

d^2 = dx^2 + dy^2

Rearranging:

dy^2 = d^2 - dx^2

$dy = \sqrt{d^2 - dx^2}$

$dy = \sqrt{3.85^2 - 3^2} = 2.41 km$

The angle of the displacement vector is:

cos(a) = dx/d

a = arccos(dx/d)

a = arccos(3/3.85) = 38.8°

7 0

3 years ago