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3 years ago

Some help please physics

Physics

2 answers:

salantis [7]3 years ago

3 0

My best guess is A There is missing a time unit in the question. I know that 4.4 *5 = 21 so that would be my best guess.

REY [17]3 years ago

3 0

The car's AVERAGE speed is (21/2)=10.5 m/s. (Zero at the beginning, 21 at the end.). In order to cover 50m at an average speed of 10.5 m/s, it takes (50/10.5)=4.76 seconds. It took 4.76 seconds to accelerate to 21 m/s^2, so the average acceleration is (21/4.76)=4.2 seconds. You probably had a formula in class that would take you to 4.4, but this is the way I think it through without a lot of formulas.

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A horizontal spring with spring constant 210 Nm is compressed by 20 cm and then used to launch a 250 g box across the floor. The

Damm [24]

Answer:

ugmd = 1/2 kx²

d = (1/2 kx²) / (ugm)

= (1/2 * 250 N/m * (0.2 m)²) / (0.23 * 9.81 m/s² * 0.3 kg)

= 7.4 m

ugmd = 1/2 mv²

v = √2ugd

= √(2(0.23)(9.81 m/s²)(7.4 m)

= 5.8 m/s

Explanation:

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3 years ago

A crane lifts a 545 kg piano up into a high-rise apartment 75.0 meters above the ground. In order to do so, 5350 Newtons were ap

vodka [1.7K]

Answer:

Work done to pull the piano upwards is 401250 J

Explanation:

Work is done against the gravity to pull the piano upwards

So here we can say that work done is

$W = mgH$

here we know that

$mg = 5350 N$

also we know that

H = 75 m

now we have

$W = 5350 \times 75$

$W = 401250 J$

7 0

3 years ago

Caitlin is riding her bike. Which of the following statements tells what is happening?

gtnhenbr [62]

What are the following statements? If there's one that mention a description of current action, or motion, that's your answer.

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3 years ago

Can you find the magnetic field based on force? a straight segment of wire 35.0 cm long carrying a current of 1.40 a is in a uni

Lostsunrise [7]

The force exerted by a magnetic field on a wire carrying current is:
$F=ILB \sin \theta$
where I is the current, L the length of the wire, B the magnetic field intensity, and $\theta$ the angle between the wire and the direction of B.

In our problem, the force is F=0.20 N. The current is I=1.40 A, while the length of the wire is L=35.0 cm=0.35 m. The angle between the wire and the magnetic field is $53 ^{\circ}$ , so we can re-arrange the formula and substitute the numbers to find B:
$B= \frac{F}{IL \sin \theta}= \frac{0.20 N}{(1.40 A)(0.35 m)(\sin 53^{\circ})}=0.51 T$

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2 years ago

Which ONE of the following pairs of physical quantities consists of one scalar and one vector quantity?

lyudmila [28]

Answer:

speed and acceleration

Explanation:

speed is a scalar quantity

acceleration is a vector quantity

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2 years ago