All categories

3 years ago

I don’t understand I need help asap

Physics

1 answer:

hammer [34]3 years ago

3 0

For the first question, you got them right, for the two you left blank, initial(beginning) velocity: 2 m/s the final velocity is: 12 m/s

You might be interested in

A 1.7m long barbell has a 20kg weight on its left and a 35kg weight on its right. (a) If you ignore the weight of the bar itself

Levart [38]

Answer:

(a) 1.08 m

(b) 1.06 m

Explanation:

Step 1: calculate the center of gravity from 20kg mass

Let the center of gravity from 20kg mass = X

Applying the principle of moment; clockwise moment = ant-clockwise moment

20*X = 35*(1.7-X)

20X = 59.5 - 35X

55X = 59.5

X = 59.5/55

X = 1.08 m

Ignoring the weight of the bar, the center of gravity is 1.08m from left end of the barbell.

Step 2: calculate the center of gravity from 20kg mass, if the 8.0kg mass of the barbell in considered.

Applying the principle of moment

$(20*X)+\frac{X}{2}(\frac{8}{1.7}) = 35(1.7-X) + (\frac{1.7-X}{2})(\frac{8}{1.7})$

$20X + 2.353X = 59.5 -35X +2.353(1.7-X)$

20X +2.353X = 59.5 -35X + 4 - 2.353X

59.706X = 63.5

X = 63.5/59.706

X = 1.06 m

considering the weight of the bar, the center of gravity is 1.06m from left end of the barbell.

4 0

2 years ago

A roller coaster begins at the top of a hillIf it accelerates at the rate of 2m/s ^2 And has a mass of 2000kg, what net force is

Luden [163]

The correct answer to the question is : 4000 N

EXPLANATION:

As per the question, the mass of the roller coaster is given as m = 2000 kg

The acceleration of the roller coaster is given as a = 2m/s2

We are asked to calculate the net force acting on the roller coaster.

From Newton's second laws of motion,we know that net external force acting on a particle is equal to the product of mass with acceleration of the particle.

Mathematically it is written as-

F = ma

Hence,net force acting on the roller coaster is calculated as-

F = 2000Kg×2m/s2

= 4000 N.

Here, Newton (N) is the unit of force.

Hence,net force acting on the roller coaster is 4000 N.

5 0

3 years ago

Dwight uses a spring (k = 70 N/m) on a horizontal surface to make a launcher for model cars. The spring is attached to a holder

kramer

Part A)

As we know that spring force is given by

F = kx

here x = stretch in the spring from natural length

So here when spring reaches to its natural length

Force due to spring = 0

so acceleration = 0

Part b)

When spring is compressed from its natural length it will have elastic potential energy in it

so it is given by

$U = \frac{1}{2}kx^2$

now we know that there is no friction in it so maximum kinetic energy of the launcher must be equal to the elastic potential energy of the spring

$KE = \frac{1}{2}kx^2$

here we have

k = 70 N/m

x = 0.4 m

$KE = \frac{1}{2}(70)(0.4)^2$

$KE = 5.6 J$

Part c)

Now to find the speed we know that

$KE = \frac{1}{2} mv^2$

$5.6 = \frac{1}{2}0.3v^2$

$v = 6.11 m/s$

so its speed is 6.11 m/s

8 0

3 years ago

Read 2 more answers

A factory has 1200 workers of which 720 are male and the rast are female what percent of workers are female

umka21 [38]

Answer:

Percent of Female Workers = 40%

Explanation:

The percentage of the female workers in the given group of workers can be easily found by the following formula:

$Percent\ of\ Female\ Workers = \frac{No.\ of\ Female\ Workers}{Total\ No.\ of\ Workers}\ x\ 100\%$

where,

Total No. of Workers = 1200

No. of Female Workers = Total Workers - No. of Male Workers

No. of Female Workers = 1200 - 720 = 480

Therefore,

$Percent\ of\ Female\ Workers = \frac{480}{1200}\ x\ 100\%$

Percent of Female Workers = 40%

7 0

2 years ago

A weight lifter lifts a 345 N set of weights from ground level to a position over his head, a vertical distance of 1.89 m. How m

Pavlova-9 [17]

Answer:652.05 J

Explanation:

Given

Weight of lifter $W=345 N$

vertical distance move $h=1.89 m$

Work done in lifting the weight is equal change in Potential Energy of weight

Change in Potential Energy $=m g h$

$\Delta PE=345 \times 1.89=652.05 J$

therefore work done is equal to $652.05 J$

3 0

3 years ago