Please I need the answers for this paper As soon as possible

homework 04 – KHALEEFOH, FAHAD – Due: Feb 26 2017, 11:00 pm (Central time) 1

Question 1, chap 4, sect 5.

part 1 of 4 10 points

A ball of mass 0.4 kg, initially at rest, is kicked directly toward a fence from a point 20 m away, as shown below. The velocity of the ball as it leaves the

kicker’s foot is 17 m/s at angle of 53 ◦ above the horizontal. The top of the fence is 7 m high. The kicker’s foot is in contact with the ball for 0.03 s. The ball hits nothing while in flight and air resistance is negligible. The acceleration due to gravity is 9.8 m/s2.

b

20 m

7 m

17 m /s

53 ◦

b

b

b

b

b

b

b

b b

b b

b b b b b b

b b

b

Determine the magnitude of the average net force exerted on the ball during the kick. Answer in units of N.

Question 2, chap 4, sect 5.

part 2 of 4 10 points

Determine the time it takes for the ball to reach the plane of the fence. Answer in units of s.

Question 3, chap 4, sect 5.

part 3 of 4 10 points

How far above the top of fence will the ball pass? Answer in units of m.

Question 4, chap 4, sect 5.

part 4 of 4 10 points

What is the vertical component of the ve- locity when the ball reaches the plane of the fence? Answer in units of m/s.

Question 5, chap 4, sect 5.

part 1 of 2 10 points

A ship maneuvers to within 2.45 × 103 m of an island’s 1.76 × 103 m high mountain peak and fires a projectile at an enemy ship 6.07 × 102 m on the other side of the peak, as illustrated. The ship shoots the projectile with an initial velocity of 2.53 × 102 m/s at an angle of 73.2◦. The acceleration of gravity is 9.81 m/s2 .

25 3 m /s

73.2◦

2450 m 607 m

1760 m

Note: Figure is not drawn to scale a) How close to the enemy ship does the

projectile land? Answer in units of m.

Question 6, chap 4, sect 5.

part 2 of 2 10 points

b) How close (vertically) does the projectile come to the peak? Answer in units of m.

Question 7, chap 4, sect 5.

part 1 of 1 10 points

A target lies flat on the ground 7 m from the side of a building that is 10 m tall, as shown below. The acceleration of gravity is 10 m/s2 . Air

resistance is negligible. A student rolls a 7 kg ball off the horizontal

roof of the building in the direction of the target.

homework 04 – KHALEEFOH, FAHAD – Due: Feb 26 2017, 11:00 pm (Central time) 2

7 m

1 0 m

v

1 0 m

The horizontal speed v with which the ball must leave the roof if it is to strike the target is most nearly

1. v =

√ 5

7 m/s.

2. v = 7 √ 3 m/s.

3. v = 7 √ 5 m/s.

4. v = 7 √ 3

3 m/s.

5. v = 3 √ 7 m/s.

6. v = 7 √ 2

2 m/s.

7. v =

√ 2

7 m/s.

8. v = 2 √ 7 m/s.

9. v = 7 √ 2 m/s.

10. v =

√ 3

7 m/s.

Question 8, chap 4, sect 5.

part 1 of 2 10 points

A bomber flies horizontally with a speed of 124 m/s relative to the ground. The altitude of the bomber is 4460 m and the terrain is level. Neglect the effects of air resistance. The acceleration of gravity is 9.8 m/s2 . a) How far from the point vertically un-

der the point of release does a bomb hit the ground? Answer in units of m.

Question 9, chap 4, sect 5.

part 2 of 2 10 points

b) At what angle from the vertical at the point of release must the telescopic bomb sight be set so that the bomb hits the target seen in the sight at the time of release? Answer in units of ◦.

Question 10, chap 4, sect 5.

part 1 of 1 10 points

A 0.98 kg rock is projected from the edge of the top of a building with an initial velocity of 12.4 m/s at an angle 60◦ above the horizontal. The building is 7.39 m in height. Assume: The ground is level and that the

side of the building is vertical. The accelera- tion of gravity is 9.8 m/s2 .

B u il d in g

x

60 ◦

12 .4 m /s

7 .3 9 m

At what horizontal distance, x, from the base of the building will the rock strike the ground? Answer in units of m.

Question 11, chap 4, sect 5.

part 1 of 1 10 points

A golf ball is hit at ground level. The ball is observed to reach its maximum height above ground level 8.8 s after being hit. 0.73 s after reaching this maximum height, the ball is observed to barely clear a fence that is 381 ft from where it was hit. The acceleration of gravity is 32 ft/s2 . How high is the fence?

Answer in units of ft.

homework 04 – KHALEEFOH, FAHAD – Due: Feb 26 2017, 11:00 pm (Central time) 3

Question 12, chap 4, sect 5.

part 1 of 3 10 points

Neglect: Air friction. Your teacher tosses a basketball. The ball

gets through the hoop (lucky shot).

b

ℓ

2 .2 0 5 m

3 .0 4 8 m

18 m /s

46 ◦

b

b

b

b b

b b

b b

b b b b b b b b b

b b

Figure: Not drawn to scale. How long does it take the ball to reach its

maximum height? Answer in units of s.

Question 13, chap 4, sect 5.

part 2 of 3 10 points

How long does it take the ball to reach the hoop? Answer in units of s.

Question 14, chap 4, sect 5.

part 3 of 3 10 points

What is the horizontal length ℓ of the shot? Answer in units of m.