I need help with physic worksheet!!! What are the answers and for the ones i filled out, are they correct????!!!!

If Sally is standing on a 200m tall cliff and throws a ball at 40m/s at a 30° angle to the horizontal: a. What is the ball's ini

Irina-Kira [14]

Answer:

(a) 20 m/s (j) m/s

(b) 20√3 m/s (i) m/s

(c) 2.04 s

(d) 20.4 m

Explanation:

In order to solve the problem, you have to apply the <em>Projectil Motion</em> equations.

For part (a) and (b) you have to obtain the components of the initial velocity vector. The direction forms a 30° angle to the horizontal and the modulus (speed) was given. Therefore:

Applying trigonometric identities (Because the initial velocity is the hypotenuse of a right triangle with angle 30° to the horizontal)

Vx: 40Cos(30°)=20√3 m/s

Vy:40Sin(30°)= 20 m/s

The initial velocity in the y direction is: 20 m/s (j) m/s

The initial velocity in the x direction is: 20√3 m/s (i) m/s

Where i and j are the unit vectors.

For part (c) you have to apply the following vertical motion equation:

Vy=Voy-gt

where Voy is the initial velocity, g is gravity and t is the time

The ball reaches its max height when Vy=0 therefore:

0=Voy-gt

Solving for t:

t=Voy/g=20/9.8= 2.04 seconds

For part (d) you have to apply the other vertical motion equation which is:

y=yo+Voyt-0.5gt²

Where yo is the initial position.

Replacing t=2.04 s, yo=0 m, Voy=20 m/s and solving for y:

y=0+(20)(2.04)-(0.5)(9.8)(2.04)²

y=20.4 m

3 0

3 years ago

Biologists use ball-and-stick models to study complex molecules by representing atoms with balls and bonds with sticks. DNA is a

AleksAgata [21]

One of the major limitations of using the ball and stick model for DNA, is that within a single double stranded segment of DNA, one would have to use many many balls to represent atoms that are present in the sugar phosphate backbone, along with all of the main atoms that compose the nitrogenous bases of DNA, we also cannot construct or show the helical form of DNA, by using balls and sticks as well.

7 0

3 years ago

Match these items. 1 . full moon a visible half-circle 2 . first-quarter moon darkest phase of the moon 3 . 13 degrees when the

konstantin123 [22]

Answer:

1. First-quarter moon.

2. New moon.

3. Full moon.

4. 13 degrees.

5. 29 1/2 days.

Explanation:

A moon can be defined as the natural satellite of planet earth that shines as a result of the sun's reflected light, as it revolves around the earth from west to east in 29½ days.

1. First-quarter moon: a visible half-circle.

2. New moon: darkest phase of the moon.

3. Full moon: when the the Earth is between the sun and the moon.

4. 13 degrees: this is a measurement of how far the moon advances each day in orbit.

5. 29 1/2 days: the time the Earth must rotate to return to same position relative to the moon.

6 0

3 years ago

how much work www does the motor do on the platform during this process? enter your answer in joules to four significant figures

soldi70 [24.7K]

The motor in the platform works for W=1885J during this process.

<h3>What is joules?</h3>

The amount of energy expended when a force of one newton is applied across a displacement of one meter is known as a joule. A joule is equal to one watt of electricity emitted or lost over the course of one second. The British thermal unit (Btu) is sometimes used to express energy. the work- or energy-measurement unit derived from the SI. The energy required to accelerate a body with a mass of one kilogram over a distance of one meter using one newton of force is equal to one joule. Additionally, one joule is equal to one watt-second.

<h3>What is joules formula?</h3>

The energy required to exert one newton of force through one meter is measured in joules. For instance, the energy required to lift a one-kilogram object one meter is given by E = Fd = (ma)d = mgd = (1 kg)(9.8m/s2)(1 m) = 9.8 kg m/s2 = 9.8 joules.

To know more about Joules visit:

brainly.com/question/25947916

#SPJ4

4 0

2 years ago

1.60 kg frictionless block is attached to an ideal spring with force constant 315 N/m . Initially the spring is neither stretche

Tatiana [17]

Answer:

(a). The amplitude of the motion is 0.926 m.

(b). The block’s maximum acceleration is 182.31 m/s².

(c). The maximum force the spring exerts on the block is 291.69 N.

Explanation: