Answer:
1 and 3
Explanation:
At the point of hitting the tennis ball by the racquet, the force by the hit is acting on the ball.
Since there is a strong wind, the force exerted by the air will act on the tennis ball as it journeys to the ground in the opponents court.
Also, since the tennis ball undergoes a downward motion before it touches the ground, a downward force of gravity also acts on the ball.
After the tennis ball has left contact with the racquet, the force by the hit ceases to act on the ball since they are no longer in contact. However, <em>the downward force of gravity and the force exerted by the air still act on the tennis ball before it touches the ground. </em>
Therefore, the correct choice is:
1 and 3
So what we can do is apply the<span> Hooke's law wich states that
F = -kx ( P.S the -ve sign means opposite in direction )
Also we will need to determine the spring's constant with the formula:
k = F / x
Where F = the force ( = 20 N )
x = the displacement of the end of the spring from it's position ( = 0.20 m )
k = the spring's constant ( = unknown )
So this would be: k = 20 / 0.20 = 100 N/m
The period of oscillation of 4 kg : T = 2 * pi * square root m / k
T = 2 * pi * square root 4 / 100
T = 1.256 seconds
Hope it helps</span>
Answer:
Carbon is stored in all living things, the ocean, the atmosphere, soil and a lot of rock. 99.9 per cent of carbon is stored in rock, mostly as limestone. After rock, the ocean is the next biggest storage site with 38,000 billion tonnes of dissolved CO2. Soil stores three times as much carbon as all the world's plants.
Answer:All the forces are acting. The force due to which the car stops that is between road and tire is "friction".
Explanation: