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# Laveeza

Questions0

A high school senior who loves hearts and art( but cannot draw)

• ### The temperature of a substance does not change as it condenses. Write 2 - 3 sentences to explain why this happens at a molecular level.?

Chemistry8 months ago

• ### How much more heat is needed to boil 5.0 kg?

How much more heat is needed to boil 5.0 kg of water than is needed to melt it? The latent heat of vaporization for water is 2260 kJ/kg, and the latent heat of fusion is 333 kJ/kg. Show your work.

• ### In general, the gravitational potential energy for a planet orbiting a star is given?

A planet orbits a star with the path shown below.

a. On the axis below, draw the general shape of the graph of the planet's gravitational potential energy as it completes one orbit. Start the graph where the planet is shown in the diagram above. (2 points)

GPE on y axis and t on x axis

b. In general, the gravitational potential energy for a planet orbiting a star is given byU=-Gm(planet)m(star)/r . The maximum distance of this planet from its star is 700,000,000 km, and the minimum distance is 600,000,000 km. The mass of the planet is 4 × 1022 kg, and the mass of the star is 5 × 1031 kg. How much does the GPE change during one full orbit? (3 points)

c. A comet of mass 2 × 108 kg is pulled toward the star. If the comet's inital velocity is very small, and the comet starts moving toward the star from 700,000,000 km away, how fast is it going right before it hits the surface of the star? (Assume that it does not lose any mass by melting as it approaches the star.) (3 points)

• ### d. At what angle do the cars move after the collision? ?

A car of mass 1000 kg is heading east at 25 m/s. It collides with a car of mass 1200 kg heading north at 30 m/s. When the cars collide, they stick together.

a. What is the total momentum of the system before the collision? Remember that momentum is a vector quantity, and write the momentum in component notation, with x and y unit vectors. (1 point)

X=-1000*25=-25000m/s

Y=1200*30=36000m/s

36000-25000=11000m/s

b. What is the total momentum of the system after the collision? Write the momentum in component notation, with x and y unit vectors. (1 point)

Total momentum=11000m/s, x=-25000m/s y=36000m/s

c. What is the velocity of the cars after the collision? Write the velocity in component notation, with x and y unit vectors. (1 point)

V=11000/2200=5m/s

d. At what angle do the cars move after the collision

plz check my answers and correct me if i am wrong.

Physics9 months ago
• ### a. What is the momentum of the system before the collision? (Write it in component form.) (0.5 points)?

In a game of pool, the cue ball moves at a speed of 2 m/s toward the eight ball. When the cue ball hits the eight ball, the cue ball bounces off with a speed of 0.8 m/s at an angle of 20°, as shown in the diagram below. Both balls have a mass of 0.6 kg.

a. What is the momentum of the system before the collision? (Write it in component form.) (0.5 points)

P=2*.6=1.2m/s

The momentum before the collision was 1.2 towards the 8 ball.

b. What is the momentum of the system after the collision? (0.5 points)

P=.8*.6=.48m/s

c. Write the velocity of the cue ball after the collision in component form. (1 point)

V=.48/1.2=.4m/s

d. What is the x-component of the velocity of the eight ball after the collision? (1 point)

e. What is the y-component of the velocity of the eight ball after the collision? (1 point)

f. At what angle does the eight ball travel after the collision? (1 point)

160 degrees

g. What is the magnitude of the eight ball's velocity after the collision? (1 point)

0

correct me if i am wrong with any of the above answers. please

• ### Puck 1 is moving 10 m/s to the left and puck 2 is moving 8 m/s to the right. They have the same mass, m.?

a. What is the total momentum of the system before the collision? (Write your answer in terms of the mass, m.) (0.5 points)

10+8=18

b. What is the total momentum of the system after the collision? (Write your answer in terms of the mass, m.) (0.5 points)

2m left

c. Write puck 1's velocity after the collision in component form. (1 point)

2m

d. What is the y-component of puck 2's velocity after the collision? (1 point)

Y=8m/2m=4m

e. What is the x-component of puck 2's velocity after the collision? (1 point)

f. At what angle does puck 2 move after the collision? Determine the angle and draw it on the diagram. (1 point)

g. What is the magnitude of puck 2's velocity after the collision? (1 point)

correct me if I'm wrong with any of the above answers

• ### If there is no friction, what is the acceleration of the crate?

April works at the grocery store. She needs to move a heavy crate of bananas (m = 65 kg) to the produce section. She drags the crate along the floor by applying a force of 280 N at an angle of 35° above the horizontal.

a. If there is no friction, what is the acceleration of the crate? (5 points)

280/65=4.3

b. If the coefficient of kinetic friction between the crate and the floor is 0.4, what is the acceleration of the crate? (5 points)

i donot know if i did A right please correct me if i am wrong.

• ### A spring has a spring constant of 130 N/m. You place a book of mass 1.2 kg on the spring and compress it 0.4 m. ?

a. How much elastic potential energy is stored in the spring? (3 points

Pe=1/2kx^2=1/2*130*0.4^2=10.4

b. You release the book and it moves vertically upward. How fast is it moving when it passes the natural length of the spring? (4 points)

c. How high does the book go, compared with the natural length of the spring? (4 points)

• ### A stuntman drives a car of mass 885 kg east with a speed of 40 m/s. ( only part c needed plz answer in 2 days)?

a. If the car accelerates at a rate of –3 m/s2, how long will it take the car to go 200 m? (3 points)

vf = √[(40 m/s)² + 2(- 3 m/s²)(200 m)]

vf = 20 m/s

vf = vi + at

vf - vi = at

(vf - vi)/a = t

t = (vf - vi)/a

t = (20 m/s - 40 m/s)/- 3 m/s²

t = 6.666666667 s

b. The stuntman drives the car off a 120 m cliff while going 40 m/s. How long will it take the car to land? (3 points)

t=120/40=3s

c. How far horizontally from the cliff will the car land? (4 points)

( I only need part c and correct me if i am wrong with any of the above answers)

• ### Vector is at a 5° angle and has a magnitude of 18. Describe this vector using vector notation. (Use the x and y symbols.) ?

x and y has a vector sign on it.

• ### can somebody check my answers (high school physics)?

You are trying to push a 14 kg canoe across a beach to get it to a lake. Initially, the canoe is at rest, and you exert a force over a distance of 5 m until it has a speed of 2.1 m/s.

a. How much work was done on the canoe? (2 points)

W=mgh=14*9.8*5= 686J

b. The coefficient of kinetic friction between the canoe and the beach is 0.25. How much work was done by friction on the canoe? (3 points)

w=-1/2(14)(2.1)^2= -30.87J

c. How much work did you perform on the canoe? (3 points)

686-30.87= 655.13J

d. What force did you apply to the canoe? (2 points)

applied force

Physics9 months ago
• ### (need answer in 2 days please).You throw a javelin at a speed of 23 m/s at an angle of 40° above the horizontal.?

You throw a javelin at a speed of 23 m/s at an angle of 40° above the horizontal.

a. How far does the javelin travel vertically? (2 points)

b. You threw the javelin from an original height of 2 m, but you accidentally threw it off a cliff that drops an additional 20 m. How long does it take the javelin to reach the ground? (4 points)

c. How far does the javelin travel horizontally from where you threw it? (4 points)