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2 years ago

I need help with these Physics problems

Physics

1 answer:

adoni [48]2 years ago

4 0

Answer:

1. 3 m

2. 27 s

Explanation:

1. "A car traveling at +33 m/s sees a red light and has to stop. If the driver can accelerate at -5.5 m/s², how far does it travel?"

Given:

v₀ = 33 m/s

v = 0 m/s

a = -5.5 m/s²

Unknown: Δx

To determine the equation you need, look for which variable you don't have and aren't solving for. In this case, we aren't given time and aren't solving for time. So look for an equation that doesn't have t in it.

Equation: v² = v₀² + 2aΔx

Substitute and solve:

(0 m/s)² = (33 m/s)² + 2(-5.5 m/s²) Δx

Δx = 3 m

2. "A plane starting from rest at one end of a runway accelerates at 4.8 m/s² for 1800 m. How long did it take to accelerate?"

Given:

v₀ = 0 m/s

a = 4.8 m/s²

Δx = 1800 m

Unknown: t

Equation: Δx = v₀ t + ½ a t²

Substitute and solve:

1800 m = (0 m/s) t + ½ (4.8 m/s²) t²

t ≈ 27 s

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Christian made some pancakes she's so 3/5 of them in the morning and 1/4 of the remainder in the afternoon is she had 300 pancak

DiKsa [7]

Christian made 1000 pancakes.

Explanation:

Let us represent the total amount of Pancake made by Christian as = K

From the problem;

Christian ate $\frac{3}{5}$ of the pancake in the morning = $\frac{3}{5}$ * K = $\frac{3}{5}$ K

We know that Christian cannot eat her pancake and at the same time have it, the remaining pancake will then be:

total amount of cake - fraction eaten

Remainder = K - $\frac{3}{5}$ K= $\frac{2}{5}$ K

In the afternoon, we know that she ate 1/4 of the remaining cake:

$\frac{1}{5}$ K* $\frac{2}{5}$ K = $\frac{1}{10}$ K

The remaining cake in the afternoon will be:

Total amount of cake remaining from morning - amount eaten in the afternoon

= $\frac{2}{5}$ K - $\frac{1}{10}$ K

= $\frac{3}{10}$ K

The fraction of the cake remaining in the afternoon is $\frac{3}{10}$ K

Since she had 300cakes left in the afternoon, then :

$\frac{3}{10}$ K= 300

K = 1000 pancakes

Therefore Christian made 1000 pancakes.

learn more:

Fractions brainly.com/question/1648978

#learnwithBrainly

4 0

3 years ago

A rod of very small diameter with a mass 2m and length 3L is placed along the xaxis with one end at the origin. An identical rod

rewona [7]

Answer:

coordinates of the center of mass for these two rods

( $x_{cm}$ , $y_{cm}$ )= ( $\frac{3L}{4}$ , $\frac{3L}{4}$ )cm

Explanation:

given

mass of a rod = 2m

length of the rod = 3L

mass of two rods = 2(2m) = 4m

radius = diameter/2 = $\frac{3L}{2}$

attached is the diagram and solution to the question

5 0

3 years ago

A ball is released from a hot air balloon moving downward with a velocity of -10.0 meters/second and a height of 1,000 meters. H

Nikolay [14]

Here, ball is released... and it is in free fall means with zero initial velocity.

We know, s = ut + 1/2 at²
Here, s = 1000 m
u = 0
a = 10 m/s2

Substitute their values,
1000 = 0 + 1/2 * 10 * t²
2000 = 10 * t²
t² = 2000 /10
t = √200
t = 14.14 s

In short, Your Answer would be 14.14 seconds

Hope this helps!

7 0

3 years ago

Read 2 more answers

Sound waves, water waves, and light waves are all alike in that they all

Paha777 [63]

Sound and water waves are longitudinal waves, they require a medium to travel through and occilate particles 90 degrees to the wave motion
Light is a transverse wave. It doesnt require a medium to travel through.
All three reflect, refract and diffract

Light is difficult to think of because it acts in ways which waves cannot explain in some cirumstances. It acts like a particle (called photons) in some conditions, but acts like a normal sound or water wave does in others. Try not to get too caught up in light being a wave or a particle because even physists dont know how to explain it yet.

7 0

3 years ago

E14. A ball rolls off a table with a horizontal velocity of 5 m/s. If

Shkiper50 [21]

a) Vertical velocity: 5.9 m/s

b) Horizontal velocity: 5 m/s

Explanation:

The motion of the ball is the motion of a projectile, which consists of two independent motions:

- A uniform motion (constant velocity) along the horizontal direction)

- A uniformly accelerated motion (constant acceleration) along the vertical direction

Here we want to find the vertical component of the ball's velocity. This can be done by using the suvat equation for the vertical motion:

$v_y = u_y +gt$

where:

$v_y$ is the vertical velocity at time t

$u_y=0$ is the initial vertical velocity (zero because the ball has been thrown horizontally)

$g=10 m/s^2$ is the acceleration of gravity (here we take downward as positive direction)

Substituting t = 0.6 s, which is the total time of flight, we find the vertical velocity of the ball just before it hits the ground:

$v_y=0+(9.8)(0.6)=5.9 m/s$

The motion along the vertical direction is an accelerated motion, because there is a force (the force of gravity) acting on the ball and that it causes an acceleration in the ball.

However, there are no forces acting in the horizontal direction on the ball (if we neglect the air resistance): this means that the acceleration of the ball in the horizontal direction is zero.

As a consequence, this also means that the horizontal component of the ball's velocity is constant during the motion.

Since the ball was thrown from the table with an initial horizontal velocity of 5 m/s, this means that the horizontal velocity of the ball just before it hits the floor is still

$v_x = 5 m/s$

8 0

3 years ago

I need help with these Physics problems​

I need help with these Physics problems