1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
4vir4ik [10]
3 years ago
13

3. A football is kicked with a speed of 35 m/s at an angle of 40°.

Physics
1 answer:
jarptica [38.1K]3 years ago
4 0

a) 22.5 m/s

The initial vertical velocity is given by:

u_y = u sin \theta

where

u = 35 m/s is the initial speed

\theta=40^{\circ} is the angle of projection of the ball

Substituting into the equation, we find

u_y = (35)(sin 40)=22.5 m/s

b) 26.8 m/s

The initial horizontal velocity is given by:

u_x = u cos \theta

where

u = 35 m/s is the initial speed

\theta=40^{\circ} is the angle of projection of the ball

Substituting into the equation, we find

u_x = (35)(cos 40)=26.8 m/s

c) 2.30 s

The time it takes for the ball to reach the maximum heigth can be found by considering the vertical motion only. This is a uniformly accelerated motion (free-fall), so we can use the suvat equation

v_y = u_y + at

where

v_y is the vertical velocity at time t

u_y = 22.5 m/s

a=g=-9.8 m/s^2 is the acceleration of gravity (negative because it is downward)

At the maximum height, the vertical velocity becomes zero, v_y =0; substituting, we find the time t at which this happens:

0=u_y + gt\\t=-\frac{u_y}{g}=-\frac{22.5}{-9.8}=2.30 s

d) 25.8 m

The maximum height can also be found by considering the vertical motion only. We can use the following suvat equation:

s=u_y t + \frac{1}{2}gt^2

where

s is the vertical displacement at time t

u_y = 22.5 m/s

g=-9.8 m/s^2

Substituting t = 2.30 s, we find the displacement at maximum height, so the maximum height:

s=(22.5)(2.30)+\frac{1}{2}(-9.8)(2.30)^2=25.8 m

e) 123.3 m

In order to find how far does the ball lands, we have to consider the horizontal motion.

First of all, the time it takes for the ball to go back to the ground is twice the time needed for reaching the maximum height:

t=2(2.30 s)=4.60 s

Then, we consider the horizontal motion. There is no acceleration along this direction, so the horizontal velocity is constant:

v_x = 26.8 m/s

Therefore, the horizontal distance travelled during the whole motion is

d=v_x t = (26.8)(4.60)=123.3 m

So, the ball lands 123.3 m far from the initial point.

You might be interested in
For which group of people might brain-powered cars allow the greatest increase in mobility?
dolphi86 [110]
Brain-powered cars?
The answer would be people who lack motor skills in their legs.
8 0
3 years ago
Read 2 more answers
6. If a bicyclist, with initial velocity of zero, steadily gained speed until reaching a final velocity of 39m/s, how far would
Bezzdna [24]

Answer:

  175 m

Explanation:

The average velocity for constant acceleration is the average of the beginning and ending velocities. That is (0+39)/2=19.5 m/s. If the bicyclist rides for 9 seconds, the distance traveled is ...

  (9 s)(19.5 m/s) = 175.5 m

She would travel 175.5 meters in that time.

7 0
3 years ago
What happens when light bounces off an object
Sever21 [200]
Absorbtion consists of when light strikes on an object and bounces off. 
3 0
3 years ago
Read 2 more answers
A small car with mass m and speed 2v and a large car with mass 2m and speed v both travel the same circular section of an unbank
Alenkasestr [34]

Answer:

(D) F/2

Explanation:

Since the circular section is unbanked, the centripedal acceleration acting on each of the cars is

a_s = \frac{v_s^2}{r} = \frac{(2v)^2}{r} = \frac{4v^2}{r}

a_l = \frac{v_l^2}{r} = \frac{v^2}{r}

Therefore the centripetal force on each car

F_s = m_sa_s = \frac{4mv^2}{r}

F_l = m_la_l = \frac{2mv^2}{r}

Since F_s = 2F_l this means the friction force required to keep the large car on the road is only half of the friction force required to keep the small car on road

So (D) F/2 is the correct answer

5 0
3 years ago
Endorphins are released through the pituitary gland? Question 2 options: True False
Pani-rosa [81]

The answer is true.

5 0
3 years ago
Read 2 more answers
Other questions:
  • Lottery balls are thrown into a hopper and are set into motion by air forced through the container. each ball has a mass of 0.00
    15·1 answer
  • Equations 22-8 and 22-9 are approximations of the magnitude of the electric field of an electric dipole, at points along the dip
    10·2 answers
  • A force of 35 N acts on a ball for 0.2 s. If the ball is initially at rest:
    15·1 answer
  • A ball, which has a mass of 1.25 kg, is thrown straight up from the top of a building 225 meters tall with a velocity of 52.0 m/
    13·1 answer
  • Please Help!
    7·1 answer
  • wo parallel conducting plates are separated by 10.0 cm, and one of them is taken to be at zero volts. (a) What is the magnitude
    5·1 answer
  • The air in this room consists of countless tiny, independent molecules. You can be sure that these air molecules won't all shift
    7·1 answer
  • Can anyone please help meee!!!​
    5·1 answer
  • What is the frequency of a pendulum of length 1.50 m at a location where 1 point the acceleration due to gravity is 9.79 m/s^2?
    9·1 answer
  • An island reports that in the year 2000 there were 240 babies born. That same year, 100 individuals died.
    11·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!